21. NAVAL OPERATIONS
21.1 BASING
21.2 MOVEMENT
21.3 EMPLOYMENT
21.4 NAVAL ACTIVITIES DURING THE MOVEMENT PHASE
21.41 PATROLS
21.42 SEA SUPPLY, OIL SHIPMENTS AND BRP GRANTS BY SEA
21.43 SEA TRANSPORT
21.44 HARBOR ATTACKS
21.5 NAVAL ACTIVITIES DURING THE COMBAT PHASE
21.51 SEABORNE INVASIONS
21.52 SHORE BOMBARDMENT
21.53 RAIDERS
21.54 ATTACKS ON ENEMY BASES
21.55 FAST CARRIER MISSIONS
21.56 SEA SUPPLY, OIL SHIPMENTS AND BRP GRANTS BY SEA
21.6 SEA ESCORT
21.7 UNINVERTING NAVAL UNITS

21.1 BASING:
21.11 Each port or port counter on the mapboard may base up to 50 naval factors. Naval bases, indicated on the mapboard by an anchor symbol, are significant only for naval construction and air defense, and have the same basing capacity as other ports.
21.111 A hex containing two ports may base up to 100 naval factors. A two‑port hex is treated as a single port for all purposes (EXCEP­TION: Air defense - 23.42).
21.112 The capacity of a port may not be voluntarily exceeded. If overstacking occurs involuntarily as a result of a failed attempt to change base during the movement phase, the excess naval units may not be used for the remainder of the player turn. The player must remedy the overstacking before the end of the redeployment phase. If he is unable to do so, excess naval units of his choice are eliminated. If overstacking occurs as a result of a failed NR, there is no opportunity to remedy the overstacking and excess naval units of his choice are eliminated.
21.113 Damaged naval units which are in the “Waiting for Repair” box of a Naval Construction Chart do not count against the basing capacity of that port.
21.114 An unlimited number of naval factors may base in a mapboard box (5).
21.12 PORT COUNTERS: A port counter acts as a port for all purposes.
21.121 PORT CONSTRUCTION: Beginning in 1942, Japan and the U.S. may each construct up to two ports each year, at a rate of one port each turn, at a cost of 3 RPs and 10 BRPs per port, subject to the following:
A. RPs: Western Allied and Japanese RPs may not be assigned to ports until the 1942 YSS, regardless of when war breaks out between Japan and the Western Allies.
B. BUILT DURING CONSTRUCTION PHASE: Ports may be constructed only during the moving player’s construction phase.
C. LOCATION: Ports may be constructed only in controlled, fully supplied one-hex islands which are part of a Pacific island group (4.74). (EXCEPTION: Ports may not be constructed in the Aleutians). No more than one port may be constructed in a hex . Ports may only be constructed in hexes which were controlled by the constructing major power at the beginning of its player turn .
21.122 CONSTRUCTION COST: The 10 BRPs required for port construction counts against the constructing major power’s construction limit.
21.123 PERMANENCY: Port counters may not be moved or destroyed once built. Captured ports may be used by the side which controls them. Port counters which are isolated remain in play.
21.124 IMMEDIATE USE PERMITTED: Port counters may be used in the player turn in which they are constructed or captured.
21.13 FRONTS:
21.131 For the purpose of naval activities, including sea supply, invasions, Magic interceptions and NRs, beaches, ports and naval units in ports are considered to be on the front which contains the water on which their hex abuts, even though the hex itself may be on a different front. For the front for which BRPs are expended for naval operations, see 9.7.
EXAMPLE: A fleet based on the north German (Baltic) coast is based on the eastern front, even though its port hex lies on the western front. A fleet based at Marseilles is based on the Mediterranean front, even though its port hex lies on the western front. In neither case would a western front offensive or limited offensive option be required for the employment of the fleets on the eastern or Mediterranean fronts, respectively.
21.132 TWO‑FRONT PORTS:
21.1321 KIEL/HAMBURG: European hex J30, which contains Kiel, Hamburg and the Kiel canal, which connected the two, is a two‑front port for all purposes. Naval units based in Kiel/Hamburg may conduct missions on either the eastern or western front. Naval units may pass through the Kiel canal while performing a naval activity if the canal was controlled at the start of the phase in which the activity is conducted.
21.1322 GIBRALTAR: Gibraltar is also a two‑front port for all purposes, is capable of sustaining missions on both the western and Mediterranean fronts, and has all the other advantages of a two‑front port. Gibraltar may be invaded from sea by naval units based in both the Mediterranean and the western front, even simultaneously. The cost of an invasion of, or a sea transport to, Gibraltar by units on the western front is charged to the Mediterranean front (73.31, 73.32).
21.1323 ISTANBUL: Istanbul is also a two‑front port for all purposes, is capable of sustaining missions in both the Black Sea and the Mediterranean, and has all the other advantages of a two‑front port. However, supply and passage between Istanbul and the Mediterranean outside the Turkish Straits is not allowed unless all the land hexes composing the strait (Z33, Z34, AA31 and BB31) are controlled by friendly forces.
21.1324 For naval interception purposes, a two-front port is considered to be on the front through which the naval activity in question passes. A naval activity to or from a two-front port may only be intercepted on the front in which the activity occurs. Thus Western Allied naval units changing base from Britain to Gibraltar could be intercepted by Axis naval units based on the western front, but not by Axis naval units based on the Mediterranean front; German naval units based in Kiel operating on the western front could be intercepted by British naval units based on the western front, but not by Russian naval units based in Leningrad.
21.14 NAVAL UNITS BASED IN THE ATLANTIC U.S. BOX: Naval units based in the Atlantic U.S. box are subject to the following restrictions.
A. Fleets based in the Atlantic U.S. box may only carry out sea transport and invasions as allowed by 21.433A and 21.512D.
B. Naval units based in the Atlantic U.S. box may conduct shore bombardment or fly carrier missions only in conjunction with an invasion (21.523, 21.553) from the Atlantic U.S. box.
C. Naval units in the Atlantic U.S. box may not conduct patrols or attempt interceptions.
D. Naval units in the Atlantic U.S. box may engage German raiders which have entered the Atlantic SW box (21.5342G).
E. Before the U.S. is at war with Germany, American naval units in the Atlantic SW box may not pursue German raiders, protect sea supply or sea escort to Britain, or otherwise interfere with Axis air or naval activity. If the U.S. is at war with Germany, American naval units based in the Atlantic U.S. box may protect sea supply and NRs traced from the Atlantic U.S. box onto the mapboard.
21.15 NAVAL UNITS BASED IN THE PACIFIC U.S. BOX: Naval units based in the Pacific U.S. box are subject to the following restrictions:
A. Fleets based in the Pacific U.S. box may only carry out sea transport and invasions as allowed by 21.433B and 21.512D.
B. Naval units based in the Pacific U.S. box may conduct shore bombardment or fly carrier missions only in conjunction with an invasion (21.523, 21.553) from the Pacific U.S. box.
C. Naval units in the Pacific U.S. box may not conduct patrols or attempt interceptions.
D. Naval units in the Pacific U.S. box may engage Japanese raiders which have entered the Pacific SW box (21.5342G).
E. Naval units based in the Pacific U.S. box may protect sea supply and NRs traced from the Pacific U.S. box onto the mapboard.
21.16 NAVAL UNITS BASED IN THE AUSTRALIA BOX: Naval units based in the Australia box may carry out naval activities, including interceptions. Such naval units appear on the board at hexes NN15 or NN24, where the coasts of Australia intersect the southern edge of the Pacific mapboard, eight hexes from the ports in the Australia box; or at hex NN31 (Noumea), ten hexes from the ports in the Australia box (5.52, 71.71). Naval units in the Australia box may engage raiders which have entered the Indian Ocean SW or Pacific SW boxes (21.5342G).
21.17 NAVAL UNITS BASED IN THE INDIA BOX: Naval units based in the India box may carry out naval activities, including intercep­tions. Such naval units appear on the board at hex CC2, where the coast of India intersects the western edge of the Pacific mapboard. This hex is eight hexes from the ports in the India box (72.71). Naval units in the India box may engage raiders which have entered the Indian Ocean SW box (21.5342G).
21.18 NAVAL UNITS BASED IN THE SOUTH AFRICA BOX: Naval units based in the South Africa box are subject to the following restrictions:
A. Naval units based in the South Africa box may not conduct offensive naval missions (EXCEPTION: Sea transport to Suez, Basra or Abadan) or attempt interceptions.
B. Naval units based in the South Africa box may protect sea supply and NRs traced from the South Africa box onto the mapboard.
C. Naval units in the South Africa box may engage raiders which have entered the Indian Ocean SW box (21.5342G).

21.2 MOVEMENT:
21.21 GENERAL RULES: The movement of naval units conducting naval activities, including base changes, naval missions and NRs, is permitted through any all-water hex. Naval movement through coastal hexsides is permitted, without regard for whether the land portion of the hex is controlled or occupied by enemy or neutral forces, subject to the following:
21.211 RESTRICTIONS ON NAVAL MOVEMENT THROUGH STRAITS: Naval movement through certain straits is prohibited as set out below. Entry into a prohibited strait to carry out a naval activity is permitted provided the naval units leave the strait on the same side they entered, without passing through the strait. The control requirements set out below must be met at the start of the phase in which the naval activity is conducted:
A. CROSSING ARROW STRAITS: Both land sides of the strait must be under friendly control. Control by a neutral is insufficient.
B. GIBRALTAR (AA7): Gibraltar must be under friendly control. Control of Spanish Morocco does not affect naval movement into or past Gibraltar.
C. SKAGERRAK (E33, F33): Hexes E33 and F33 must be under friendly control.
D. KATTEGAT (H32, H33): Copenhagen must be under friendly control; H33 must be under friendly or neutral control.
E. GULF OF FINLAND (D41, E41): Helsinki (D41) and Tallinn (E41) must be under friendly or neutral control.
F. GULF OF RIGA (G39, F40): Seaborne invasions of hex F40 and naval movement and operations to or from Parnu, the port in hex F40, require control of Saare (F39), the one-hex island off the coast of Estonia. Naval interception of naval movement and operations to or from Parnu is governed by the general provisions for interception through straits.
G. STRAIT OF OTRANTO (AA25, AA26): Brindisi (AA25) and Durazzo (AA26) must be under friendly control.
H. STRAIT OF MALACCA (DD11, EE10): Singapore must be under friendly control. Singapore itself may be invaded from the west through an enemy-controlled Strait of Malacca. Counter-interception of enemy naval interception of such invasions is not allowed.
I. SUNDA STRAIT (II10, II11): The land portions of hexes II10 (Sumatra) and II11 (Java) must be under friendly control.
21.2111 INTERCEPTIONS IN STRAITS: Naval units may enter a prohibited strait to intercept enemy naval forces entering or leaving the intercepting naval units' side of the prohibited strait, but may not intercept on both sides of the strait simultaneously. Where a single interception is not possible because passage through a strait is not permitted, the naval activity may be intercepted on each side of the strait (22.13A), but intercepting naval forces on different sides of the strait may not combine in a single interception in the strait hex. This prohibition applies to patrols in straits; patrolling forces may only intercept enemy naval activities entering or leaving the patrolling naval units' side of the prohibited strait.
21.212 SUEZ CANAL: Movement through the Suez canal is permitted if all the land hexes adjacent to the canal are controlled by friendly forces ( 88.34).
21.213 RIVERS: Naval movement through rivers is prohibited.
21.214 U.S. BOXES: Western Allied naval units may change base or redeploy to and from the Atlantic U.S. or Pacific U.S. boxes as follows:
A. Base changes are permitted only between the Atlantic U.S. box and western front ports, the Pacific U.S. box or the South Africa box.
B. Base changes are permitted only between the Pacific U.S. box and the Australia box, the Atlantic U.S. box, Dutch Harbor, Pearl Harbor, Papeete or any port constructed in the Hawaiian or Society Islands.
C.. Naval units moving to and from the Atlantic U.S. box enter and leave the board at any west edge hex from A23 to EE1, inclusive.
D. Naval units moving to and from the Pacific U.S. box enter and leave the board at any east edge hex from A59 to KK48, inclusive.
E. Redeployment between the Atlantic U.S. or Pacific U.S. box and the mapboard must terminate in or pass through a western front port or Dutch Harbor, Pearl Harbor, Papeete or any port constructed in the Hawaiian or Society Islands, respectively (28.75).
21.215 INDIAN OCEAN: Special rules govern the movement of naval units from Suez, Basra and Abadan to the Indian Ocean SW box, the India box, the Australia box and the South Africa box (25.3, 28.753, 28.754, 28.755).
21.216 AUSTRALIA, INDIA AND SOUTH AFRICA BOXES: Western Allied Naval units may move into and out of the Australia, India and South Africa boxes (21.16-18, 71.7, 72.7).
21.217 OFF-BOARD MOVEMENT: Naval units may not move off the mapboard except as follows.:
A. When moving to a mapboard box.
B. To enter a notional Western Allied port hex off the western edge of the Atlantic mapboard or the eastern edge of the Pacific mapboard as required to meet range restrictions (21.361).
C. When conducting naval activities on the western front on the European mapboard, sea supply lines and naval units may move off the western edge of the mapboard in order to avoid enemy air attack or reduce the likelihood of enemy naval interception, then reenter the mapboard on another western edge hex. Naval movement off the northern edge of the European mapboard in this manner is prohibited. Sea supply lines and naval units availing themselves of this rule are subject to air attack and naval interception or counter-interception in the normal manner while on the mapboard before entering the “virtual hexes” off the western edge of the European mapboard, after reentering the mapboard, and while in the virtual hexes themselves. The virtual hexes are taken into account when determining distances for air attacks, naval interceptions and naval counter-interceptions.
EXAMPLES: Western Allied naval units moving between Britain and Gibraltar may move off the mapboard near Britain and move back onto the mapboard near Gibraltar in order to avoid Axis air units based in Vigo. Similarly, Axis naval units based in France or Spain attempting to intercept Western Allied supply or NRs from the U.S. box north of Ireland may move off the mapboard to avoid Western Allied air units in Ireland, reentering the mapboard near their interception hex.
21.22 BASE CHANGES:
21.221 Naval units may change base during their movement phase. A naval unit may move to a port which is not operational, but the range of activities it may perform from that port is limited. All base changes are made simultaneously. Base changes are vulnerable to attack by enemy air units (23.7) and interception by enemy naval units (22.1).
21.222 Naval units which are intercepted while trying to change base and are defeated in the ensuing naval combat return to their original base, even if this results in an overstacking in the original base because of other, successful base changes, and are inverted for the remainder of the player turn. If the excess stacking is not remedied during the redeployment phase, the excess naval units are eliminated (28.523).
21.223 The new base must be within forty ( Europe) or twenty (Pacific) hexes of the old base (EXCEPTIONS: See 21.3616 for central Pacific exceptions). Base changes may cross front boundaries. The new base must have been controlled by the moving player’s side at the start of his movement phase.
21.224 Naval units may base change to and from the U.S. (5.28B), South Africa (5.38B), India (5.48B) or Australia (5.58B) mapboard boxes. Uninverted naval units are inverted if they change base from one mapboard box to another, when they change base from an SW box to a mapboard port (25.372A), or if they change base between theaters, and may not be uninverted before the end of their player turn (33.74B); naval units which are already inverted remain inverted until the end of their player turn. Naval units are not inverted if they change base from one port to another, from a port to a mapboard box or from a mapboard box to a port, provided the base change occurs within a theater, or to an SW box.
21.225 Naval base changes are made after the staging of air units and before the movement of ground units.
21.23 DISPLACED NAVAL UNITS: Naval units at bases which are occupied by enemy units are displaced to the nearest controlled port with adequate basing capacity, regardless of its supply status:
A. Should two such ports be equidistant, the owning player chooses.
B. If the nearest port is able to base only some of the displaced naval units, the owning player chooses which naval units go to that port, and the remainder go to the next closest port.
C. Naval units displaced from a two-front port choose the front to which they wish to be displaced, then go to the nearest port on that front.
D. If no such port exists within 40 (Europe) or 20 (Pacific) hexes, the displaced naval units are eliminated (EXCEPTIONS: See 21.3616 for central Pacific exceptions).
E. The owner chooses the route to the new port.
F. Damaged ships and ships on the “2” or “Launch” row of a Naval Construction Chart are displaced in the normal manner.
G. Naval units sunk in port and ships on the “3” or higher row of a Naval Construction Chart are eliminated if their base is occupied by an enemy unit.
21.231 Naval units may be displaced to the U.S., India and Australia boxes from any port from which base changes to the mapboard box are allowed. In determining whether a mapboard box is the “nearest controlled port” (21.23), the distance from the edge of the board to the mapboard box, as set out in rule 5 for each mapboard box, is taken into account.
21.232 INTERCEPTION OF DISPLACED NAVAL UNITS:
A. The movement of displaced naval units to their destination port may be attacked by eligible enemy air units and intercepted by eligible enemy naval units.
B. Displaced naval units may not abort their movement after being engaged by enemy air or naval units. Displaced naval units which withdraw from naval combat must withdraw in their entirety, without leaving any naval units behind, and then continue along the same route to their previous destination.
C. Displaced naval units are subject to air attacks as they enter each hex along the route to their destination.
D. Similarly, displaced naval units may be intercepted by additional enemy naval forces, including submarines, as they move along the route to their destination. The moving player decides whether to attempt naval interception when the displaced naval units reach the interception hex.
21.233 Displaced naval units are inverted.

21.3 EMPLOYMENT:
21.31 During any player turn, uninverted naval units which are unimpaired by supply problems may carry out one, but no more than one, of the operations set out in the Naval Activities Table in the player aids (EXCEPTION: Naval units in an SW box may be used more than once in the same turn - 25.36).
21.311 INVERSION AFTER USE: After performing any of the above functions, naval units are inverted until uninverted in accordance with 33.7 (EXCEPTION: Naval units in an SW box - 25.36).
21.312 USE OF TFs FOR NAVAL ACTIVITIES: A naval force consisting of ten or more naval factors must be in a TF in order to conduct a naval activity.
21.313 RESTRICTIONS ON FAST CARRIER OPERATIONS: Fast carriers in a naval force may only conduct operations listed in 20.32 as part of a naval force which contains at least one fast fleet factor for each fast carrier factor (EXCEPTION: Japan’s Pearl Harbor strike force - 51.12). This restriction applies only at the start of an operation. Fleet factor losses incurred once an operation has begun do not force the cancellation of the operation. A naval force may not split into smaller forces during an operation unless each new naval force meets this restriction (EXCEPTION: fast carriers withdrawing from naval combat - 22.61). Fast carriers may change base, NR, be displaced or withdraw from naval combat without accompanying fast fleet factors.
21.314 RESTRICTIONS ON DAMAGED NAVAL UNITS: Damaged naval units may not undertake any of the activities listed in the Naval Activities Table. Naval units which are damaged while conducting a naval activity may not carry units or BRPs, conduct shore bombardment, launch or recover naval air units, fire during fleet combat, participate in SW or otherwise participate in the naval activity, but are not forced to withdraw immediately and may continue to accompany undamaged naval units which are still able to carry out the naval activity.
21.315 RESTRICTIONS ON TRANSPORT ACTIVITIES: If a naval activity involving transports is aborted, contemporaneous naval operations involving transports to the destination supply zone are unaffected, but no transports may be used for naval operations relating to the destination supply zone for the remainder of the player turn.
21.32 BASE CHANGES AND SUBSEQUENT USE: A naval unit may change base during the movement phase and still perform any one of the above functions, even if it successfully engaged in naval combat during the base change (EXCEPTIONS: Patrols; naval units operating in the SW box). A naval unit which has performed one of the above functions during the movement or combat phase may still be NRed during the redeployment phase.
21.321 In the course of any one phase, a given naval unit may not return to its base and leave again, nor enter the sea portion of more than one hex targeted for sea transport or invasion (unless no alternate route to its destination is available) – even though it takes no action there. Naval units may not base change or redeploy to their original base by leaving and returning to it in order to protect a base change or activity being performed by other naval units.
21.33 RETURNING TO BASE: Naval units which survive a naval activity may, subject to stacking limits, return either to their base of origin, subject to the same range requirements as for their activity (21.36) or to any other base that was under friendly control at the start of their player turn within 20 (Europe) or 10 (Pacific) hexes of the hex in which that activity was carried out. For naval units which engaged in naval combat, the naval combat hex is used. (EXCEPTIONS: During the combat phase, naval units may not return to a base which is the target of an enemy seaborne invasion unless it is the only base available. After failed base changes, NRs or sea escorts, naval units must return to their base of origin (21.222 28.523). Western Allied naval units which escort a Murmansk convoy return to their port or mapboard box of origin - 40.48C. Naval units carrying out an operation from an SW box must return to the SW box - 5.91).
21.34 Naval units are inverted in their turn of construction and may not perform any of the 21.31 functions during the player turn they are placed on the board. Newly constructed naval units may be uninverted at the end of the player turn in which they are constructed in accordance with 33.7.
21.35 CARGO: When a player conducts a naval activity involving cargo (sea supply, sea transport, seaborne invasion, NRing ground or air units, shipping oil or BRPs grants by sea), the player must assign the cargo to a specific TF or, if the activity is being conducted by a small force of naval units not in a TF, to those naval units (referred to below as TFs).
A. UNITS, OIL AND BRPS: Cargo (ground and air units, oil counters or BRPs) must be assigned to TFs which contain enough destroyers or transports to carry them. Air units being transported or NRed may be broken down before being assigned.
B. SEA SUPPLY: Sea supply protection is assigned to a single TF.
C. TRANSPORTS: Transports are assigned to one or more TFs of the moving player’s choice, although the transports are not physically put into the TF (20.162B).
21.36 RANGE AND DISTANCES: When determining the range of naval units:
A. DISTANCES BY WATER: The distances referred to are measured by water, not as the crow flies. The route traced to meet range limits must follow the rules of naval movement (21.2).
B. FIRST HEX NOT COUNTED: The hex in which a naval unit is based is not counted as the first hex, even though naval units are considered to enter the water portion of their port hex for interception purposes.
C. PORTS: Ports used to meet range restrictions set out in 21.361 must be:
D. MAPBOARD BOXES:
21.361 RANGE RESTRICTIONS: The range of naval activities is restricted as follows (EXCEPTION: Range restrictions do not apply to countries in theaters in which they are not at war). These limits apply to both fleets and carriers. The notional hexes off the western edge of the Atlantic mapboard and the eastern edge of the Pacific mapboard are considered to be Western Allied ports for purposes of rules 21.3611-3615.
21.3611 INTERCEPTIONS, COUNTER-INTERCEPTIONS: The maximum range for naval interceptions and counter-interceptions is 40 (European) or 20 (Pacific) hexes (22.22).
21.3612 SEA SUPPLY, NRs, SEA ESCORT: There is no range limit for sea supply (30.33), NRs and sea escort (28.5), although such activities must touch a port (21.36C) at least once every 20 (Europe) or 10 (Pacific) hexes. (EXCEPTIONS: See 21.3615 and 21.3616 for exceptions in the Pacific). Islands without port access (21.37) from which units are being NRed are considered to contain ports for the purpose of meeting the range requirement for that sea escort only.
21.3613 BASE CHANGES, NAVAL DISPLACEMENT: Base changes may not exceed 40 (Europe) or 20 (Pacific) hexes. Displaced naval units may not move more than 40 ( Europe) or 20 (Pacific) hexes. (EXCEPTION: See 21.3616 for exceptions in the Pacific).
21.3614 OFFENSIVE NAVAL MISSIONS: Offensive naval missions may not exceed 40 (Europe) or 20 (Pacific) hexes, and must touch a port (21.36C) at least once every 20 (Europe) or 10 (Pacific) hexes. (EXCEPTIONS: See 21.3615 and 21.3616 for exceptions in the Pacific). In addition, the following exceptions apply specifically to seaborne invasions:
21.3615 ALLIED RANGE EXCEPTIONS IN THE PACIFIC:
A. HAWAIIAN ISLANDS: If the Western Allies control and fully supply both Midway and Johnston Island, the initial leg of a Western Allied naval activity beginning in the Hawaiian Islands may cross up to 15 hexes before touching a port (21.36C). If the Western Allies also control and fully supply Wake, the initial leg of a Western Allied naval activity beginning in the Hawaiian Islands may cross up to 20 hexes before touching a port (21.36C).
B. ALEUTIAN ISLANDS: A Western Allied naval activity between the Hawaiian Islands and the Aleutian Islands may exceed the range limit and requires no intervening port, provided the activity proceeds by the shortest route.
C. SEA ESCORT: Ground and air units in any island within naval range of the Hawaiian Islands may be NRed back to the Hawaiian Islands, with destroyers based in the Hawaiian Islands providing sea escort.
21.3616 JAPANESE RANGE EXCEPTIONS IN THE PACIFIC:
A. JAPAN:
The initial leg of a Japanese naval activity beginning in Japan may cross up to 20 hexes before touching a port (21.36C). (EXCEPTION: Midway – 21.3616B)
B. MIDWAY, JOHNSTON ISLAND, HAWAIIAN ISLANDS:
C. ALEUTIAN ISLANDS: Japanese naval activities between Japan and the Aleutian Islands may exceed the normal range limits and require no intervening port, provided the activity proceeds by the shortest route.
D. INITIAL ATTACK ON PEARL HARBOR: The patrol mission for the initial Japanese attack on Pearl Harbor (51.12) may exceed the range limit and need not touch a port every 10 hexes.
E. SEA ESCORT: Ground and air units in any island within naval range of Japan may be NRed back to Japan, with destroyers based in Japan providing sea escort.
21.3617 PORT MORESBY, SANDAKAN: Because Port Moresby and Sandakan are in jungle/mountain hexes, their maximum capacity for meeting the 21.36C range restrictions is five hexes. No naval operations or activities, other than interceptions and counter-interceptions by naval units based in Port Moresby or Sandakan, may originate in or pass through Port Moresby and Sandakan without terminating or passing through an eligible port no more than five hexes away.
21.362 FRONT BOUNDARIES IGNORED: Front boundaries have no effect on naval activities.
21.37 ISLANDS WITHOUT PORT ACCESS: Naval units may sea transport and NR ground and air units into and out of, and ground units may conduct seaborne invasion from, controlled islands which do not contain a port as follows:
A. One-hex islands.
B. Palawan, New Ireland and Halmahera, through their beach hexes as though they were ports (4.75).

21.4 NAVAL ACTIVITIES DURING THE MOVEMENT PHASE:
21.41 PATROLS:
21.411 OVERVIEW: During the movement phase naval units may move to an announced sea hex (the “patrol hex”) in order to attack enemy bases, assist in ground attacks and improve their chances of counter-intercepting enemy naval activities during the movement phase or the ensuing combat phase.
21.412 RANGE: Patrols are subject to the range restrictions for offensive operations set out in 21.3614.
21.413 PATROLS FROM MAPBOARD BOXES:
A. Patrols may not be conducted by naval units based in the U.S. or South Africa boxes.
B. Patrols may be conducted by naval units based in the India and Australia boxes. The India and Australia boxes are eight hexes from the western and southern edges of the Pacific mapboard, respectively.
21.414 COST AND TIMING:
A. BRP COST: Patrols are an offensive mission and BRPs must be paid for all participating naval units on the front containing the patrol hex (EXCEPTION: No BRP expenditure is required for patrols by submarines - 9.56A).
B. TIMING: Movement to patrol hexes, base changes (21.22) and SW naval deployments (25.31) are contemporaneous. Naval units may not change base during a movement phase in which they patrol. Naval units from different bases may, however, combine to carry out a joint patrol in the same hex. Naval units forming a joint patrol move to the patrol hex at the same time and may join at sea before reaching the patrol hex.
21.415 BASING: The patrol hex functions as the patrolling force’s base during the remainder of the movement phase and the ensuing combat phase. However, for basing purposes, a patrol is considered to have remained in its base of origin while on patrol. Naval units therefore may not change base into a base from which a patrol has been sent if the base did not have sufficient capacity to base both naval forces.
21.416 MECHANICS: Patrols are conducted using the following sequence:
A. The moving player announces all patrols, base changes and SW naval deployments (25.31). The moving player does not announce any air strikes by patrolling carriers at this time.
B. If the moving player is conducting more than one patrol, he designates the sequence in which his patrols will be conducted. The first patrolling force then moves toward its patrol hex along whatever route the moving player wishes (subject to the range restrictions for patrols - 21.3614).
C. When a patrolling force enters a new hex, the defending player may attempt naval interception of the patrolling force in the same manner as other naval activities. Naval interception is resolved before the patrolling force counterairs any defending air units from the new hex. Defending air units within air range of the interception hex therefore assist in any naval interception of the patrolling force (22.22F).
D. If naval interception occurs, naval combat is resolved normally. Both the intercepted patrolling force and any intercepting naval forces may counterair enemy air units within range of the interception hex as part of naval combat (22.41B).
E. If the patrolling force wins the naval combat, it may either continue moving to its patrol hex or abort its patrol and return to port, at the moving player’s option.
F. If the patrolling force loses the naval combat, it must return to port and is inverted for the remainder of the player turn. The victorious intercepting naval forces may remain in the interception hex as a defensive patrol (21.419) or return to port and invert for the remainder of the player turn, at the defender’s option.
G. If no naval interception occurs, a patrolling force containing fast carriers which has not yet arrived in its patrol hex may engage in one round of counterair combat against any enemy air bases within range of its hex:
H. As a patrolling force enters each hex en route to its patrol hex, the sequence set out above is repeated.
I. Once the patrolling force reaches its patrol hex, it may launch repeated counterair attacks/air strikes against all enemy bases within range of its patrol hex.
J. Before each round of counterair attacks/air strikes from the patrol hex, the defender has the option of attempting naval interception if he has not done so previously.
K. When the moving player has finished all his counterair attacks/air strikes from the patrol hex, he announces whether his patrolling force is returning to base or remaining in the patrol hex during the combat phase.
L. If a patrolling force remains in the patrol hex, the defender may attempt interception of the patrolling force, if he has not already done so. Any resulting naval combat is resolved. The loser returns to base and is inverted for the remainder of the player turn, and the victor has the option of returning to base and being inverted for the remainder of the player turn or remaining in the patrol hex during the ensuing combat phase.

As set out in the Naval Interception Table, the greatest chance of intercepting a patrolling force is when it remains in its patrol hex.

M. Defending air units that were aborted in their final round of air combat with the patrol are inverted. If the moving player is conducting more than one patrol, steps B through L are repeated for each subsequent patrol, until all patrols are resolved.

Protect your naval bases with land-based air, especially in the Pacific! In a single turn a base may be counteraired before it is attacked by a patrol, attacked by two or more separate patrols (with the exception of the initial attack on Pearl Harbor), and may be bombed again in the combat phase.

21.417 INTERCEPTION OF PATROLS: A patrolling force may be intercepted:
A. En route to and in its patrol hex (21.416C, 21.416J).
B. Once all air strikes from its patrol hex are completed if it attempts to remain in its patrol hex (21.416L).
21.4171 The defender may not attempt interception of a patrolling force at one point, then attempt interception again later with the same or other naval forces except as allowed by 22.13.
21.418 OFFENSIVE PATROL FUNCTIONS: Each patrolling naval and naval air unit may be used as follows. Naval and naval air units may participate in naval combat without impairing their ability to perform these operations:
21.4181 AIR UNITS:
A. As a patrolling force moves to its patrol hex, patrolling naval air units may counterair enemy bases (21.416G).
B. Once a patrolling force reaches its patrol hex, patrolling naval air units may launch repeated counterair attacks/air strikes against all enemy bases within range of its patrol hex (21.416I).
C. Naval air units in a patrolling force which remains at sea (21.416L) may also do any one of the following:
21.4182 NAVAL UNITS:
A. COUNTER-INTERCEPTIONS: Patrolling forces which remain at sea (21.416L) may counter-intercept only by supporting intercepted friendly naval forces (22.163).
B. SUCCESSFUL SUPPORT: A patrolling force which supports an intercepted friendly naval force joins the supported naval force and adopts its mission once any naval combat is resolved (EXCEPTION: Raiders).
C. UNSUCCESSFUL SUPPORT: A patrolling force which fails to reach an intercepted friendly naval force prior to the end of naval combat and therefore does not engage in naval combat returns to its patrol hex and may not attempt to counter-intercept again until a later phase.
D. DIVIDING A PATROL: A patrolling force may divide into smaller forces to support different intercepted friendly naval forces. Part of a patrolling force may remain uncommitted.
E. RESTRICTIONS: Since patrols are contemporaneous with other patrols, base changes and SW naval deployments, they may not directly support such naval activities by counter-intercepting. Patrolling forces may not provide shore bombardment or intercept (EXCEPTIONS: Successful support - 21.4182B, Defensive patrols - 21.419).
21.4183 RETURN TO BASE PRIOR TO EXPLOITATION: All patrolling forces return to base (21.33) and are inverted for the remainder of the player turn at the end of regular combat, prior to exploitation, after all other offensive missions are resolved, (EXCEPTION: Submarine patrols may remain at sea - 21.4184).
21.4184 SUBMARINE PATROLS: Submarines may patrol in the same manner as other naval units, subject to the same restrictions as other patrols, with the following special features:
A. Submarines patrol independent of other naval forces.
B. Submarine patrols may remain at sea when other patrols return to base. If they do not return to base (21.4183), they remain at sea until they attack, engage in naval combat, or until the end of the opposing player turn, whichever comes first.
C. Each patrolling submarine at sea during the opposing player turn may be attacked in a single sortie by enemy land-based air units within range of their patrol hex during the movement phase of the opposing player’s turn, immediately after counterair attacks are resolved. Each land-based air squadron may attack once. Air cover may be flown over the patrolling submarines, but no air defense dice roll is made by the defender. Submarines may not be attacked by enemy carrier-based naval air units or enemy fleet units.
D. A submarine patrol may counter-intercept in the same manner as other patrols (21.4182A). During the opposing player turn, a submarine on patrol is considered to be a defensive patrol (21.4195).
E. German submarines may not remain on patrol on the western front during the Allied player turn if Germany conducted submarine warfare in the Atlantic SW box during the Axis player turn.
21.419 DEFENSIVE PATROLS:
21.4191 A defending naval force which intercepts and defeats a patrolling force may, at the defender’s option, remain in the interception hex until the end of regular combat in the ensuing combat phase. The defending naval force is then considered to be on defensive patrol. A victorious defending naval force which returns to base during the move­ment phase is inverted for the remainder of the player turn.
21.4192 A defensive patrolling force may attempt intercep­tions or counter-interceptions from its patrol hex in the same manner as it would from port (22.14F). The defensive patrolling force may attempt to intercept during the sea supply or sea transport segments of the movement phase and again during the combat phase.
21.4193 The ability of a defensive patrolling force to intercept an enemy patrol, then intercept again as permitted by 21.4192, is an exception to the rule that naval units may only intercept once each turn. Only one successful 21.4192 interception is permitted each turn.
21.4194 If a defensive patrol intercepts an enemy naval activity, it may be counter‑intercep­ted normally in any hex along its interception route, including its patrol hex. Otherwise defensive patrols may not be counter-intercepted.
21.4195 Submarines on patrol during the opposing player turn are considered to be defensive patrols and may attempt to intercept any enemy naval activity during any turn segment, in the same manner as they would from port (22.14F).

21.42 SEA SUPPLY, OIL SHIPMENTS AND BRP GRANTS BY SEA: During initial supply determination, the moving player may conduct the following naval activities:
21.421 SEA SUPPLY:
A. SEA SUPPLY FROM PORTS: Sea supply lines from ports do not require naval units (30.361).
B. SEA SUPPLY FROM MAPBOARD BOXES: Each Western Allied sea supply line from a mapboard box requires the use of one transport in the relevant shipping area (30.365).
21.422 OIL SHIPMENTS: Oil counters may by shipped by sea. One transport (Western Allies, Japan) or three destroyer factors (European Axis) are required to sea escort each oil counter shipped by sea (20.64A, 33.43B).
21.423 BRP GRANTS: Western Allied BRP grants may be made by sea. One Western Allied transport is required to sea escort each BRP grant of up to five BRPs (20.64D).
21.424 PROTECTION OF NAVAL ACTIVITIES: The above naval activities may be protected (21.65F, G, 30.36).

21.43 SEA TRANSPORT:
21.431 During the movement phase, destroyers may sea transport ground or air units by moving them from a controlled port, eligible island (21.37) or eligible mapboard box to another controlled port, eligible island or mapboard box.
21.432 RANGE: Sea transports are subject to the range restrictions for offensive operations set out in 21.3614.
21.433 SEA TRANSPORT TO AND FROM MAPBOARD BOXES: Sea transport is permitted:
A. Between the Atlantic U.S. box and a western front port, through the Atlantic Ocean.
B. Between the Pacific U.S. box and Dutch Harbor, the Hawaiian Islands (Hawaii, Kauai, Maui, Necker, Oahu) or the Society Islands (Bora Bora, Tahiti), through the Pacific Ocean.
C. Between the India and Australia boxes and the Pacific mapboard.
D. Between the India box and Suez, Basra or Abadan, through the Indian Ocean.
E. Between the Australia box and Suez, Basra or Abadan, through the Indian Ocean.
F. Between the South Africa box and Suez, Basra or Abadan, through the Indian Ocean.
21.434 DESTROYER AND TRANSPORT REQUIREMENTS:
A. One destroyer factor is required to sea transport each ground or air factor, except as set out below.
B. Two destroyer factors are required for each ground or air factor sea transported to or from the U.S., South Africa, India and Australia boxes.
C. Sea transport to or from a mapboard box also requires one transport from the SW box through which the sea transport passes for every five ground or air factors sea transported (20.64C).
21.435 MECHANICS:
A. Destroyers used to sea transport need not be based at the base of embarkation.
B. Destroyers used to sea transport may move from their base to the base of embarkation, then to the base of debarkation, subject to range restrictions (21.3614).
C. There may be more than one base of embarkation for one sea transport mission; but there may be only one base of debarkation. Different bases of debark­ation require indepen­dent missions.
D. Both the base of embarkation and debarkation must have been under friendly control at the start of the transporting player’s player turn.
E. Other naval units may accompany destroyers conducting sea transport in order to protect the sea transport mission. Such naval units are subject to the same basing and movement restrictions as the destroyers conducting the sea transport.
F. Sea transport may not be used to land forces on a bridgehead counter unless the bridgehead hex also contains a port (EXCEPTION: One- and two-hex islands without port access - 21.37).
G. A unit may not be sea transported from one location to another, then sea transported again from the new location, in the same turn.
H. Units which are sea transported debark during the movement phase and are subject to stacking limitations at the end of the movement phase.
21.436 UNSUCCESSFUL SEA TRANSPORTS:
A. Naval units on a sea transport mission which are intercepted and abort their mission or withdraw from naval combat before arriving at the base of embarkation return to their original base.
B. If interception and defeat in naval combat occurs after the embarkation of the transported ground or air units, but before debarkation at the intended destination, the naval units on the sea transport mission and the surviving units they are carrying return to the base of embarkation, the transported units debark, and the naval units return to their original base.
C. Subject to the normal rules of supply, ground units which return to their base of embarkation incur the usual movement factor cost for debarking (21.437), but otherwise may move and conduct attacks, and air units may fly missions from the base of debarkation.
21.437 SEA TRANSPORT OF GROUND UNITS:
A. MOVEMENT: Ground units may use their full movement capability during the player turn in which they are sea transported. Ground units may move to the port of embarkation before being sea transported, prior to the movement of other ground units, but may not conduct overruns as they do so. Only ground units which have sufficient movement factors to meet the costs of embarkation (if any) and debarkation may be sea transported. Ground units may move after being sea transported, if permitted by their remaining movement factors, and may engage in overruns, offensive ground attacks or attrition in conjunction with other ground units .
B. STACKING: The number of ground units which may sea transport from or to a single port is not limited by stacking limits.
C. SUPPLY: Ground units which are partially supplied or subject to an army oil effect may not be sea transported.
D. INVASIONS PROHIBITED: Ground units which are sea transported may not be used to invade in the same turn.
21.438 SEA TRANSPORT OF AIR UNITS:
A. BASING: The air unit must begin the player turn in the base of embarkation. The base of debarkation is treated as the air unit’s new base. A sea transport is the equivalent of staging: a sea transported air unit may not stage to the base of embarkation or from the base of debarkation. Inverted air units may be sea transported.
B. STACKING: The transportation of air units is prohibited if the transportation would result in too many air factors in the base of debarkation.
C. OPERATION: Air units which have been sea transported may operate normally during the ensuing combat phase. There is no reduction in range to reflect the movement cost of debarking, which only applies to ground units.

21.44 HARBOR ATTACKS:
21.441 TIMING: Harbor attacks are resolved by the moving player during the movement phase, after attacks from patrols are completed, but prior to the completion of base changes and the movement of naval units to and from SW boxes.
21.442 HARBOR ATTACK RESULT REQUIRED: To carry out a harbor attack, the moving player must have achieved the required research result (EXCEPTION: The initial German harbor attack - 21.444).
21.443 MECHANICS: Harbor attacks are resolved using the Harbor Attack Table (see the Research Tables and Player Aids). When a harbor attack is made, the following sequence is followed:
A. The attacker announces the target hex, the nature of the attack and all his applicable modifiers.
B. The defender announces all his applicable modifiers, including the application of a counter-intelligence result.
C. Both players may play tactical cards in an attempt to gain a codebreaking advantage (48.32B).
D. The harbor attack is resolved.
21.444 INITIAL GERMAN HARBOR ATTACK: Germany begins the game with the ability to make a harbor attack against one enemy target. This attack may be made in Fall 1939 or any subsequent turn, provided no other harbor attacks have been made. The execution of this attack does not modify subsequent harbor attacks.


21.5 NAVAL ACTIVITIES DURING THE COMBAT PHASE:
21.51 SEABORNE INVASIONS:
21.511 OVERVIEW: During the combat phase, ground units in a controlled port, eligible island or eligible mapboard box may be carried by destroyers and invade an eligible invasion hex (21.5154).
21.512 RANGE: Seaborne invasions are subject to the range restrictions for offensive operations set out in 21.3614. In addition, the following exceptions apply:
A. COMMANDOS: The range of a commando unit using its special capability to invade a port is restricted to 10 ( Europe) or 5 (Pacific) hexes.
B. DUTCH HARBOR: Dutch Harbor may not be used as a base for seaborne invasions.
C. ALEUTIANS: For Japan to invade Dutch Harbor from Japan, it must control and fully supply another Aleutian island. The invasion must pass through the required island en route to Dutch Harbor.
D. PERMITTED MAPBOARD BOX INVASIONS: Seaborne invasions are permitted:
E. PROHIBITED MAPBOARD BOX INVASIONS: Seaborne invasions from the South Africa box or into a mapboard box are prohibited.
21.513 DESTROYER AND TRANSPORT REQUIREMENTS:
A. UNDEFENDED HEXES: One destroyer factor is required to carry each invading ground factor if the invasion hex is not occupied by an enemy ground unit.
B. DEFENDED HEXES: Two destroyer factors are required to carry each invading ground factor, including ground units which do not participate in the initial invasion combat, if the invasion hex is occupied by an enemy ground unit.
C. INVASIONS FROM MAPBOARD BOXES:
21.514 MECHANICS:
A. Destroyers used for seaborne invasions need not be based at the base of embarkation.
B. Destroyers used for seaborne invasions may move from their base to the base of embarkation, then to the invasion hex, subject to range restrictions (21.3614).
C. There may be more than one base of embarkation for a seaborne invasion; but there may be only one invasion hex. Different invasion hexes require indepen­dent missions.
D. Other naval units may accompany destroyers conducting seaborne invasions in order to protect the invasion mission or provide shore bombardment to support the invasion. Such naval units are subject to the same basing and movement restrictions as the destroyers conducting the seaborne invasion.
E. Invading ground units must start their turn in a controlled, fully supplied port, eligible island hex (21.37) or eligible mapboard box . Unlike ground units which are sea transported, they may not move to the port of embarkation.
F. Ground units which are partially supplied or subject to the army oil effect may not invade. Air units may not invade.
21.515 RESTRICTIONS: In addition to the restrictions on naval movement set out in 21.21, seaborne invasions are subject to the following restrictions:
21.5151 WEATHER:
A. Seaborne invasions which involve naval movement through western and eastern front sea hexes are prohibited during winter turns, regardless of the location of the invasion hex.
B. Winter invasions of Aleutian islands are prohibited.
EXAMPLES: Winter invasions of hex T10 (in Portugal), Casablanca and French North Africa from Britain through the Straits of Gibraltar are prohibited. A winter invasion of U19 (in southern France) is allowed if the naval movement of the invasion forces is confined to the Mediterranean.
21.5152 INVASIONS LIMITED TO 1:1 ATTACKS OR GREATER: Seaborne invasions of a hex containing an enemy unit may only be made if the resulting ground combat is at 1:1 odds or more. If an adverse ground combat result causes the odds to drop below 1:1, the invasion is aborted and no further ground combat is allowed. The naval units on the seaborne invasion mission and the surviving ground units they are carrying return to the base of embarkation, the ground units debark, and the naval units return to their original base.
21.5153 ENEMY NAVAL UNITS:
A. If, after all air, harbor and atomic attacks against the naval units in an invasion hex in the turn of invasion are resolved, the invasion hex contains an enemy TF or ten or more undamaged enemy naval factors which are not in a TF, the invasion may not be carried out.
B. Submarines, ASW and transports are not counted.
C. Naval units in Lorient or Famagusta do not prevent seaborne invasion, as the beaches in those hexes are on a different coastline from the ports.
D. An airdrop which drives the defending naval units out of the invasion hex does not permit invasion.
E. If the target hex does not contain enough enemy naval factors to prevent the invasion, invasion is permitted and the enemy naval factors are displaced if the attacker occupies the invasion hex (21.23). Prior to displace­ment, the enemy naval factors may attempt interception.
21.5154 ELIGIBLE INVASION HEXES: Seaborne invasions may only be conducted against a beach hex, Gibraltar, Singapore or one-hex islands (EXCEPTION: Commandos may invade undefended port hexes if the Western Allied CTL is two or more).
21.516 DEFEAT OF SEABORNE INVASIONS AT SEA:
A. Naval units on a seaborne invasion mission which are intercepted and abort their mission or withdraw from naval combat before arriving at the base of embarkation return to their original base.
B. If interception and defeat in naval combat occurs after the embarkation of the invading ground units, but before the seaborne invasion takes place, the naval units on the seaborne invasion mission and the surviving ground units they are carrying return to the base of embarkation, the ground units debark, and the naval units return to their original base.
C. Invading ground units which return to their base of embarkation after an unsuccessful seaborne invasion may neither move from their embarkation port during the remainder of the combat phase, including during exploitation, nor participate in attrition or offensive combat.
21.517 INVASION COMBAT:
A. INVADING GROUND UNITS: Any number of ground units may participate in an invasion, up to the capacity of the invading destroyers, but no more than two of those ground units may attack the target hex by sea (EXCEPTIONS: Marines and commandos may participate in invasion combat in excess of this limit).
B. ADDITIONAL GROUND UNITS: Airborne units which drop on the target hex and ground units adjacent to the target hex by land may join with the invading forces in attacking the beach hex, although this would not affect the DM for defending against an invasion.
C. SHORE BOMBARDMENT: Invading ground units may be assisted by shore bombardment from naval factors not engaged in carrying ground units. If destroyers which originally had been carrying invading ground units engage in combat with intercepting enemy air or naval units and incur losses which result in the loss of one or more ground units, any excess destroyer factors may be used for shore bombardment to support an invasion by surviving ground units. The total number of combat factors added by shore bombardment is limited by Naval Nationality DRM, and may never exceed three times the total number of ground factors involved in the invasion attack (21.526).
D. GROUND SUPPORT: Invading ground units may receive ground support from any air units within range, including ground support from carrier-based naval air units and CVEs. The total number of combat factors added by ground support may not exceed three times the total number of ground factors involved in the invasion attack.
E. DM OF DEFENDING UNITS: Ground units defending against invasion receive a +1 DM, even if simultaneously attacked from an adjacent land hex or by airborne drop (15.32B), unless at least half of the invading force consists of marines (10.71). The defenders also receive the defensive benefit of any other terrain in their hex.
F. STRENGTH OF DEFENSIVE AIR SUPPORT TRIPLED: The strength of defensive air support flown against seaborne invasions is tripled (18.611C).
G. RESOLVING INVASION COMBAT: Invasion combat is resolved in the same manner as normal ground combat.
H. INVASION COMBAT LOSSES: Ground combat losses may be taken from ground units which took part in the invasion combat, air factors or CVEs which provided ground support or fleets which provided shore bombardment. The attacker may not take ground combat losses from embarked units which did not participate in his initial attack or from destroyers which carried the invading ground units. Uncommitted ground units and the destroyers carrying them are not affected by the results of invasion combat.
I. PLACEMENT OF A BRIDGEHEAD COUNTER: If the invasion hex was enemy-controlled and at least one initially invading ground unit survives invasion combat and occupies the invasion hex, a bridgehead counter may be placed on the invasion hex. If the target hex contained no enemy ground units, success is automatic and a bridgehead counter may be placed (EXCEPTION: Invasions of friendly hexes - 31.22).
J. OCCUPATION OF INVASION HEXES: All invading ground units which survive the invasion must occupy the invasion hex. Ground units aboard the invasion fleet which did not participate in the attack are also placed on the invasion hex. Up to five non-specialized ground units may occupy the invasion hex if a bridgehead counter has been placed (12.13), plus three specialized units (12.12) (EXCEPTIONS: No more than one non-specialized ground unit may occupy an invaded non-port Pacific one-hex island, plus three specialized units; no more than two non-specialized ground unit may occupy an invaded Pacific one-hex island that contains a port, plus three specialized units (12.11B, 12.12)).
K. SURPLUS UNITS RETURN TO PORT: Ground units may return to any port within range of an invasion hex in order to avoid overstacking. If an invasion hex is overstacked at the end of the combat phase, excess units of the invading player’s choice are eliminated.
21.518 EXPLOITATION FROM INVASION HEXES: A breakthrough may be achieved on an invasion hex if all of the following conditions are met:
A. At least one of the ground units taking part in the initial invasion combat is an armor unit with its mechanized component currently intact;
B. The armor unit has a CTL of one or more;
C. The armor unit is involved in the final round of invasion combat; and
D. At least one ground unit taking part in the initial invasion combat survives and occupies the invasion hex.
21.5181 WHICH ARMOR UNITS MAY EXPLOIT: If a breakthrough is created by an invading armor unit, other armor units in reserve aboard the invasion fleet could then exploit. Armor units adjacent to the invasion hex by land may only exploit if invasion hex was also attacked by land in combination with the invasion. In this case, the required armor unit may come from either the invasion force or the adjacent land units.
21.5182 UNDEFENDED INVASION HEXES: Breakthrough and exploitation from an invasion hex is allowed even if the invasion hex was undefended.
21.5183 CTL REDUCTION OF EXPLOITING ARMOR: The CTL of armor units exploiting from a breakthrough created by a seaborne invasion is reduced by one during the attacker’s exploitation. This CTL reduction applies whether the seaborne invasion was conducted against an occupied or unoccupied hex (16.15).
21.519 RESTRICTIONS ON INVADING UNITS:
A. NON-EXPLOITATION MOVEMENT AND ATTACKS: Movement into hexes contiguous to the invaded hex and attacks against enemy units in such hexes are permitted only during exploitation. Invading ground units may not make offensive ground attacks out of their invasion hex unless they exploit.
B. ATTRITIONS: Ground units which invade a hex are not counted for attrition.

21.52 SHORE BOMBARDMENT:
21.521 OVERVIEW: During the combat phase, shore bombardment may be used by an attacker to support a seaborne invasion by ground units. Shore bombardment may not be used to support non-invasion ground attacks, airdrops or exploitation attacks.
21.522 RANGE: Shore bombardment is subject to the range restrictions for offensive operations set out in 21.3614.
21.523 SHORE BOMBARBARDMENT FROM MAPBOARD BOXES: Shore bombardment by naval units based in mapboard boxes is:
A. Permitted from the U.S. in conjunction with invasions from the U.S. boxes.
B. Permitted from the India and Australia boxes.
C. Prohibited from the South Africa box.
21.524 MECHANICS: Naval units used for shore bombardment need not be based at the same base as the destroyers carrying the invading ground units.
21.525 EFFECT OF SHORE BOMBARDMENT: For every three naval factors providing shore bombardment, one combat factor is added to the strength of the attacker’s ground units when determining the odds for ground combat.
21.526 LIMITS ON SHORE BOMBARDMENT: The total number of combat factors added to a ground attack by shore bombardment depends on the Naval Nationality DRM of the naval units providing shore bombardment. This limitation is distinct from the limitation on ground support from air units.
A. NAVAL NATIONALITY DRM OF ONE: For naval units with a Naval Nationality DRM of one, the number of combat factors added to a ground attack by shore bombardment may not exceed the total number of ground factors involved in the invasion attack.
B. NAVAL NATIONALITY DRM OF TWO: For naval units with a Naval Nationality DRM of two, the number of combat factors added to a ground attack by shore bombardment may not exceed twice the total number of ground factors involved in the invasion attack.
C. NAVAL NATIONALITY DRM OF THREE OR MORE: For naval units with a Naval Nationality DRM of three or more, the number of combat factors added to a ground attack by shore bombardment may not exceed three times the total number of ground factors involved in the invasion attack.
D. MIXED DRMs: If naval units with different Naval Nationality DRMs conduct shore bombardment, the above limits are applied to each category of Naval Nationality DRMs; naval units with a Naval Nationality DRM of one are limited to the number of ground factors involved in the invasion attack; naval units with a Naval Nationality DRM of two are limited to twice the number of ground factors involved in the invasion attack, taking into account any shore bombardment provided by naval units with a Naval Nationality DRM of one. Similarly, the amount of shore bombardment provided by naval units with a Naval Nationality DRM of three or more has to take into account shore bombardment provided by naval units with lower Naval Nationality DRM.

EXAMPLE: Three British ground factors invade, supported by Free French and British naval units. The Free French naval units have a Naval Nationality DRM of one (58.624); the British naval units have a Naval Nationality DRM of two. Nine Free French naval factors can provide shore bombardment (adding three combat factors to the invasion attack); another nine British naval factors can then provide shore bombardment.

21.527 The attacker may combine ground support from air units or CVEs with shore bombardment to assist his attacking ground units. Ground support from naval air units may be used to supplement shore bombardment, with remnants from both being added together, provided the permitted limits on ground support or shore bombardment are not exceeded.
21.528 LOSSES TO NAVAL UNITS PROVIDING SHORE BOMBARDMENT:
21.5281 Naval units which provide shore bombardment may be eliminated (light ships) or damaged (heavy ships) as a result of ground combat in the same manner as other units. For each fleet factor lost, two other fleet factors are prohibited from providing shore bombardment in subsequent combat rounds. If a heavy ship incurs damage because one factor of ground combat loss is attributed to it (21.5282C), the remaining factors in that heavy ship are counted towards this prohibition.
21.5282 Ground combat losses may be taken by fleets which provide shore bombardment only if this results in the elimination of a light ship or the damaging of a heavy ship:
A. DESTROYERS: One destroyer factor is eliminated for each factor of ground combat losses attributed to destroyers. Destroyers carrying invading ground units may not be taken as ground combat losses.
B. CRUISERS: One cruiser is eliminated for every two factors of ground combat losses attributed to cruisers. Ground combat losses may only be assigned to a cruiser if this results in the sinking of that cruiser.
C. HEAVY SHIPS: Only one factor of ground combat losses may be assigned to each heavy ship. This damages the heavy ship.
21.5283 LIMIT ON SHORE BOMBARDMENT LOSSES: Ground combat losses may be distributed as desired by the attacking player from among participating ground, air and naval units when satisfying ground combat loss requirements, without regard for air or naval unit types or base of origin, provided the losses in factors assigned to fleet factors that provided shore bombardment do not exceed the value in combat factors of the shore bombardment component of the ground attack.
EXAMPLES: Two invading 3‑2 infantry units and 36 fleet factors providing shore bombardment (6 + 12 = 18) attack a 2‑3 armor unit on a beach hex (2 x 3 = 6) at 3:1 odds. If an “Ex” result occurs, the defender loses his 2‑3 armor unit and the attacker loses both 3‑2 infantry units, one 3‑2 infantry unit and three fleet factors, or six fleet factors (his choice), subject the requirements of
21.5282.
If the defender had a 3‑2 infantry unit and a 1‑2 infantry unit, the odds would be 18:12 = 1:1. If an “Ex” result occurred, both defending infantry units would be eliminated and the attacker could choose to lose both 3‑2 infantry units and six fleet factors, one 3‑2 infantry unit and nine fleet factors or 12 fleet factors; in all three cases, the surviving fleet factors would return to port.

21.53 RAIDERS:
21.531 OVERVIEW:
A. Eligible Axis naval units may attempt to raid Allied shipping by moving into the Atlantic, Indian Ocean or Pacific SW boxes.
B. Raiding is an Axis offensive operation carried out during the combat phase, at the same time other naval missions are conducted, prior to the resolution of SW combat .
C. For the purpose of determining the front for BRP expendi­tures:
21.532 RAIDER GROUPS:
A. ELIGIBLE SHIPS: Cruisers, capital ships and fast carriers may raid; five-factor battleships, destroyers and slow ships may not.
B. ATLANTIC SW BOX: Only German naval units based in a western front port may raid into the Atlantic.
C. INDIAN OCEAN SW BOX: Up to three German or Italian ships may raid from Suez if the Axis control the Suez canal and Ethiopia. Up to three Japanese ships may raid from each of Colombo, Madras and Singapore.
D. PACIFIC SW BOX: Japanese ships may raid into the Pacific SW box from Townsville, Noumea, Suva, or any port in the Hawaiian Islands. Up to three Japanese ships may raid from each such port.
E. COMPOSITION: Each raider group may consist of no more than three ships, no more than one of which may be a fast carrier. Each two-factor cruiser is considered one ship.
21.533 MOVING TO AN SW BOX:
A. RAIDS FROM DIFFERENT PORTS: More than one raider group may raid from a single port. Ships based in different ports may rendezvous in a hex and form a raider group prior to entering an SW box.
B. MOVEMENT OF RAIDERS TO SW BOXES: Raiders must move from port to the SW box before they may attack enemy transports (EXCEPTION: 21.5331). Raider groups may not travel together for mutual support (22.141).
C. PRIORITY: If more than one raider group attempts to raid in the same SW box, the raiding player must designate one raiding group as the first raider, another as the second raider, and so on. If the European Axis and Japanese both raid in the Indian Ocean and cannot agree, the Japanese decide the order of raiding groups. The first raiding group is less likely to be intercepted (see the Raider Table - 21.5342).
D. ON-BOARD INTERCEPTION: Raiders may be attacked by air or intercepted on the board while moving to an SW box. If the raider defeats the on-board air attacks or interception and enters the SW box, it may be engaged in the SW box (21.534). Naval units raiding from Bergen or Scapa Flow move directly to the Atlantic SW box and are not subject to air attack or on-board interception as they do so.

A raider may only be intercepted on the board if a favorable interception modifier applies.

21.5331 PLACEMENT OF RAIDERS DURING OPENING SETUP: Germany may place one or more of the Graf Spee, Lutzow or Scheer in the Atlantic SW box during its opening setup. These may be grouped together or in separate raiding groups. Once placed, these ships must raid, with Germany paying one BRP for each raiding ship during its Fall 1939 combat phase.
21.534 DEFENDING AGAINST RAIDERS IN AN SW BOX:
21.5341 FIRST ENGAGEMENT ATTEMPT: After the defender has resolved any naval interceptions of the moving player’s other naval missions, the defender may roll one die for each raider group and consult the Raider Table to determine how many defending ships engage each raiding group. The defender may choose not to oppose a raiding group, but once the defender has decided to oppose a raider group, he cannot change his mind.
A. If the modified die roll for a raider group is “0” or less, the raider group escapes detection and may attack the defending transports (21.5361A).
B. If the modified die roll for a raider group is “1” or more, the raider group may be engaged by one or more defending ships.
21.5342 DETERMINING WHICH SHIPS ENGAGE:
A. For each raiding group for which the modified die roll was “1” or greater, the defender rolls a number of dice equal to his modified die roll and consults the Raider Table to determine which types of ships engage the raider.
B. Only fast ships may engage raiders during the first engagement.
C. No more than one fast carrier may engage a raider group in each engagement attempt, for a maximum of one fast carrier in the first engagement and a second fast carrier in the second engagement. The fast carrier must be fully operational and a sufficient number of light fleet factors must also engage the raider (21.313); unless both these requirements are met, another ship must be used (21.5342D).
D. If there is no eligible ship available of the type permitted by one of the defender’s die rolls, either because no such ship is available or because the defender rolled a “6” and is not permitted to engage with a fast carrier because there are not sufficient light ships available to accompany the carrier (21.5242C), the defender must choose a lesser die roll and send the ship associated with that die roll. He may not refuse to send out ships.
E. Once the defender determines the types of ships which engage all raiding groups, the defender chooses which eligible ships actually engage in naval combat with the raiders. If a ship is eligible to engage more than one raider group, the defender chooses which raider group to engage with that ship.
F. Naval units which engage raiders are not subject to attack by land-based enemy air units or interception by enemy naval units as they move to a SW box.
G. Defending ships must be uninverted in one of the following locations. All uninverted defending ships in the listed locations are eligible, and in some circumstances may be required, to engage raiding groups (EXCEPTION: Defending ships in ports which are not operational may not engage raiding groups).

Raider Table - 21.5342

One die is rolled for each raider group to determine how many defending naval units are able to engage that raider group. The die roll is modified as follows:

General modifiers:

-3

Automatic

+1

for each additional raider group operating in the SW box (+1 for the second group, +2 for the third group, etc.)

+1

if the raider group contains three ships

+1

for each defender air range research result

Additional Atlantic modifiers:

+1

the U.S. is at war with Germany

+1

for every 6 CVEs in the Atlantic SW box (round down): 0-5: 0; 6-11: +1; 12-17: +2; 18-23: +3; 24+: +4

Additional Indian Ocean modifier:

+1

Japanese raiders based in Singapore.

+1

for every 3 CVEs in the Indian Ocean SW box (round down): 0-2: 0; 3-5: +1; 6-8: +2; 9-11: +3; 12+: +4. Each operational search AAS and NAS in the India box is equivalent to one CVE.

Additional Pacific modifier:

+1

for every 3 CVEs in the Pacific SW box (round down): 0-2: 0; 3-5: +1; 6-8: +2; 9-11: +3; 12+: +4. Each operational search AAS and NAS in the Australia box is equivalent to one CVE with respect to Japanese raiders entering the Pacific SW box off the southern edge of the Pacific mapboard (only).

Additional modifier for German and Italian raiders:

+/-1

Ultra codebreaking advantage

Additional modifier for Japanese raiders:

+/-1

Magic codebreaking advantage

Modified results of “1” or greater permit defending ships to engage the raider group in question.

The types of defending ships which engage each raiding group is determined by rolling one die. The defender must choose a lesser die roll result if no eligible ship of the required type is available.
Only fast ships may engage raiders during the first engagement; slow ships may engage a returning raiding group containing damaged ships.

1

One destroyer factor

2

2-factor cruiser or 2-factor battlecruiser

3

3-factor battleship or battlecruiser

4

4-factor battleship

5

5-factor battleship

6

One fast carrier of any size and an equivalent number of light ship factors


EXAMPLE: The Bismarck and a cruiser raid in the Atlantic. The modified raider die roll is “4”, which permits four British ships to engage the raider group. Four dice are rolled: the die rolls to determine which ships engage are a “2” (a cruiser or a 2-factor battlecruiser), a “3” (a 3-factor battlecruiser), a “4” (a 4-factor battleship) and a “6” (a fast carrier and an equivalent number of light ship factors). If the British player didn’t have a 4-factor battleship available, he could select a 3-factor battlecruiser, a 2-factor cruiser or battlecruiser, or even a destroyer factor.

21.535 NAVAL COMBAT BETWEEN RAIDERS AND DEFENDING NAVAL UNITS: One round of naval combat is then resolved between each raiding group and the defending naval units which engage that raider group:
A. Naval combat involving raiders uses a simplified naval combat procedure (see 22.35).
B. The +/-1 DRM associated with protecting transports (22.552B) applies to this engagement.
21.536 RAIDER EFFECTS:
21.5361 WHEN RAIDERS MAY ATTACK TRANSPORTS:
A. NO DEFENDING NAVAL UNITS: If a raiding group is not engaged by defending naval units, all the naval units in that raiding group may attack the defender’s transports.
B. ALL DEFENDERS SCREENED OR ELIMINATED: If a raiding group is engaged by defending naval units, one or more raiding ships may be withheld from naval combat in the hope of later attacking the defender’s transports.
21.5362 RAIDER GROUPS FIRE SEPARATELY: Combat by raiders which are eligible to attack the defender’s transports is resolved as follows:
A. CARRIERS: Any fast carrier in a raiding group resolves a single air strike, using the Naval Attack Table (22.55). If more than one raider group contains a fast carrier, more than one air strike is resolved. No air defense roll is made by the transports unless the defender has an Air Defense research result.
B. HEAVY AND LIGHT SHIPS: The heavy and light ships in each raiding group combine and resolve a single fleet combat dice roll against the defending transports, using the Naval Attack Table (22.55). This process is repeated for each raiding group. The defending transports do not fire.
C. MODIFIERS: Nationality DRMs apply to air strikes (21.5362A) and fleet combat (21.5362B) by raiders against transports. Transports are considered to be carrying out a naval activity which reduces their effectiveness and the fleet combat modifier associated with such activities applies (22.552B).
21.5363 WHEN RAIDERS PROHIBITED FROM ATTACKING TRANSPORTS: Raiding naval units may not attack the defender’s transports if any of the defender’s unscreened naval units survive naval combat with the raider group in question, even if all the defending naval units are damaged.
21.537 RETURNING TO PORT:
A. Once the first round of naval combat between each raider group and any defending naval units which engaged them and raider attacks against enemy transports are both resolved, all raiding groups must then attempt to return to port. Raiders may not remain at sea.
B. Each raider group attempts to return to port as a single group.
C. Damaged defending naval units must disengage after the first round of naval combat and return to port. Undamaged defending naval units may fight a second round of naval combat against the raiding group they engaged, together with any additional defending naval units which succeed in engaging that raiding group (21.538).
D. Damaged ships must disengage after the first round of naval combat and return to port.
21.538 SECOND ENGAGEMENT ATTEMPT:
A. Before raiders return to port, a second die roll is made on the Raider Table for each raiding group, using the same modifiers as for the first raider die roll for that group, and the process set out in rule 21.534 is repeated, with the following differences:
B. After naval combat is resolved or declined by the defender, all surviving raiders and defending naval units return to any eligible ports or mapboard boxes (21.5342G) and may be attacked by defending air units and intercepted by defending naval units as they do so (EXCEPTIONS: German raiders returning to port in Fall 1939 after having started the game at sea and German raiders returning to Bergen or Scapa Flow may not be attacked by air or intercepted as they return to port – 22.11A). Surviving raiders may not make a second attack against the defender’s transports in that turn.

21.54 ATTACKS ON ENEMY BASES: See 23.6.

21.55 FAST CARRIER MISSIONS:
21.551 OVERVIEW: During the combat phase, fast carriers may move to a sea hex (the “mission hex”) so their NAS may attack enemy bases or assist in regular ground combat.
21.552 RANGE: Fast carrier missions are subject to the range restrictions for offensive operations set out in 21.3614.
21.553 FAST CARRIER MISSIONS FROM MAPBOARD BOXES: Fast carrier missions by naval units based in mapboard boxes are:
A. Permitted from the U.S. boxes only if the fast carriers accompany a seaborne invasion mission from the U.S. box.
B. Permitted from the India and Australia boxes.
C. Prohibited from the South Africa box.
21.554 COST AND TIMING:
A. BRP COST: Fast carrier missions are an offensive mission and BRPs must be paid for all participating naval units on the front containing the mission hex (EXCEPTION: No BRP expenditure is required for submarines that accompany fast carrier missions - 9.56A). If the fast carriers accompany a seaborne invasion or shore bombardment mission, the mission hex is considered to be on the front containing the land portion of the invasion hex.
B. TIMING: Fast carrier missions are contemporaneous with other offensive naval missions in the combat phase. Independent fast carrier missions are announced at the same time as other offensive missions in the combat phase. Fast carriers accompanying seaborne invasion or shore bombardment missions need not be independently announced , even if their naval air units will perform a carrier air mission. Missions are not assigned to carrier air units until after all combat arising from enemy naval interceptions has been resolved.
21.555 MECHANICS:
A. A naval force containing fast carriers must always contain at least as many fast fleet factors as fast carrier factors (21.313).
B. Fleet factors accompanying fast carriers are subject to the same basing and movement restrictions as the fast carriers.
C. Naval units conducting a fast carrier mission may not intercept or counter-intercept, and engage in naval combat only if they are intercepted.
D. Participation in naval combat does not impair the ability of surviving naval air units to perform a carrier air mission.
E. Fast carrier missions return to base (21.33) after the resolution of regular combat, prior to exploitation.
21.556 CARRIER AIR MISSIONS: Carrier-based naval air units may fly an air mission while the carrier is at sea during the combat phase. Subject to the restriction that each naval air unit may perform only one mission, different air missions may be conducted by carrier-based naval air units from a single naval force, and carrier-based naval air units from different fast carrier missions and patrols that remained at sea during the combat phase (21.4181C) may combine in a single attack against the same target. Each naval air unit may:
A. Conduct a counterair attack or air strike against a single enemy base, flying multiple sorties.
B. Provide ground support or intercept defensive air support in relation to a non-exploitation attack during regular combat.
21.557 DISTINCT FROM PATROLS: Fast carrier missions differ from patrols (21.41) as follows:
A. Patrols are initially conducted during the movement phase; fast carrier missions are conducted only during the combat phase.
B. Fast carrier missions from a U.S. mapboard box are allowed in conjunction with seaborne invasions from the U.S. box; patrols are not.
C. Naval units may change base before conducting a fast carrier mission; patrolling naval units may not.
D. Naval air units on a fast carrier mission may not counterair enemy bases while en route to the mission hex except as a part of naval combat.
E. Naval units on a fast carrier mission may not counter-intercept in support of intercepted friendly naval forces.
F. Naval air units on a patrol may launch repeated counterair attacks and air strikes against all enemy bases within range of the patrol hex; naval air units on a fast carrier mission may only fly counterair attacks and air strikes against a single enemy base.

21.56 SEA SUPPLY, OIL SHIPMENTS AND BRP GRANTS BY SEA: During post-combat supply determination, sea supply lines may be traced, oil counters shipped and BRP grants made by sea in the same manner as during initial supply determination (21.42).

21.6 SEA ESCORT:
21.61 OVERVIEW: Ground and air units which redeploy across water and BRPs and oil counters which are shipped across water must be sea escorted by either destroyers or transports, as set out below (EXCEPTIONS: No sea escort is required to cross rivers or crossing arrows). Sea escort is permitted to and from mapboard boxes as set out in rules 28.75-28.758. See also rule 5.
21.62 RANGE: Sea escorts are subject to the range restrictions set out in 21.3612.
21.63 TIMING: Naval activities requiring sea escort may be carried out at the following times during the moving player’s turn:
A. Movement phase, during initial supply determination: Oil shipments and BRP grants by sea.
B. Combat phase, during post-combat supply determination: Oil shipments and BRP grants by sea.
C. Redeployment phase: NRing ground and air units.
21.64 DESTROYER AND TRANSPORT REQUIREMENTS:
A. One destroyer factor is required to sea escort each ground or air factor.
B. Three destroyer factors are required to sea escort each oil counter shipped by sea by the European Axis (33.43B) .
C. One transport is required to sea escort every five ground or air factors (round up) (20.64C).
D. One transport is required to sea escort every five BRPs (round up) granted by sea (20.64D). Destroyers are not required to escort BRP grants by sea.
E. One transport is required to sea escort each oil counter shipped by sea by the Western Allies or Japan (20.64A).
F. Destroyers must be used for sea escort which begins and ends on a mapboard, except as set out below.
G. Transports may be used to sea escort between the following locations provided they were controlled by the escorting player at the start of its player turn:
H. Transports must be used for sea escorts which:
I. Sea escorts using transports may be continued using destroyers based in the port where the portion of the sea escort using transports ends. Similarly, sea escorts using destroyers may be continued using transports if transports are available to sea escort from the port where the portion of the sea escort using destroyers ends.

Example: The Western Allies may sea escort a ground unit from the Atlantic U.S. box to the India box in a single redeployment, using Atlantic transports for the leg from the U.S. box to Gibraltar, DDs based in Gibraltar for the leg from Gibraltar to Suez, and Indian Ocean transports for the leg from Suez to the India box.

21.65 MECHANICS:
A. Destroyers used for sea escort must either be based in the embarkation hex or reach the embarkation point on the initial leg of the sea escort.
B. Transports used for sea escort may only have one base of embarkation and one destination.
C. Cargo being sea escorted must be embarked at a controlled, fully supplied port, eligible island hex (21.37) or mapboard box.
D. Cargo being sea escorted must be debarked at a controlled, partially or fully supplied port, eligible island hex (21.37) or mapboard box or, for oil shipments, a bridgehead placed by seaborne invasion.
E. Oil counters and BRP grants may be sea escorted to a destination that is not yet supplied at the same time post-combat supply is traced to the destination. If the supply line is cut, the oil shipments and BRP grants are aborted.
F. Other naval units may accompany sea escorts in order to protect the sea escort. Such naval units are subject to the same basing and movement restrictions as destroyers conducting sea escort.
G. Units, oil counters and BRPs sea escorted by transports may also be protected by naval units based in the SW box containing the transports. If more than one such transport is being used to sea escort units, the sea escorting player must indicate which naval units in the SW box are protecting which sea escort before enemy air or naval attacks on the sea escort are attempted. The use of naval units in an SW box for the protection of sea escort does not affect their ability to perform other functions in that SW box (25.36).
H. Ground and air units being sea escorted must either be in or be able to redeploy by land or air to the port or eligible island hex (21.37) from which they are being sea escorted.
I. Sea escorts to different destinations are carried out separately, as are sea escorts and NRs (28.32). Contemporaneous sea supply, oil shipments and BRP grants by sea to the same destination may be combined for mutual protection.

EXAMPLE: An American 3-2 infantry unit is in Port Moresby. The Allied player wishes to use destroyers to NR the 3-2 infantry unit from Port Moresby to the Philippines. At least three Allied destroyer factors are required for sea escort. These destroyers could not be based in the Philippines at the start of the redeployment phase. If they were, they could NR to Port Moresby, but could not provide sea escort for the 3-2 infantry unit in Port Moresby until the following turn. Planning ahead, the Allied player might have moved the required destroyers to a port within 10 hexes of Port Moresby during the movement phase, then used them for sea escort that same turn.
If Japanese naval units intercepted the sea escort of the 3-2 infantry unit from Port Moresby, and won the resulting naval combat, the 3-2 would return to Port Moresby, unless the Allies had fewer than three surviving destroyer factors, in which case, regardless of who won the naval combat, the 3-2 infantry unit would be eliminated.

21.66 UNSUCCESSFUL SEA ESCORTS:
A. Naval units used for sea escort which are intercepted and abort their mission or withdraw from naval combat before arriving at the base of embarkation return to their original base.
B. If interception and defeat in naval combat occurs after the embarkation of the sea escorted ground or air units, oil counters or BRP grants, but before debarkation at the intended destination, the naval units used for sea escort and their surviving cargo return to the base of embarkation, the cargo debarks, and the naval units return to their original base.
C. If the number of destroyer factors used for sea escort drops below the number required as a result of enemy action, the cargo being sea escorted is eliminated. If a transport used for sea escort is eliminated, the cargo being sea escorted is eliminated (22.82).
D. Ground and air units which return to their base of embarkation may SR and TR from that base.

21.7 UNINVERTING NAVAL UNITS:
21.71 UNINVERSION LIMITS: The ability to uninvert naval units is directly related to the number of oil counters assigned to naval purposes. See 33.7 for the relationship between oil consumption and uninversion capacity, restrictions on uninversion and exemptions from uninversion limits.