Rule 23. AIR-NAVAL OPERATIONS

23. AIR-NAVAL OPERATIONS 23.1 OVERVIEW
23.2 AIR COVER
23.3 COMBAT AIR PATROL
23.4 AIR ATTACKS ON NAVAL UNITS
23.5 LAND-BASED AIR ATTACKS ON NAVAL BASES
23.6 CARRIER ATTACKS ON ENEMY BASES
23.7 CARRIER ATTACKS ON ENEMY NAVAL UNITS AT SEA
23.8 LAND-BASED AIR ATTACKS ON ENEMY NAVAL UNITS AT SEA

23.1 OVERVIEW:
23.11 EMPLOYMENT OF AIR UNITS: Air and naval units interact in a variety of ways:
A. ASSIST NAVAL INTERCEPTION (search AAS and land-based NAS): Land-based search AAS and NAS may spot enemy naval activities and increase the number of dice rolled for naval interceptions (22.231A). Spotting does not invert the search AAS or NAS.
B. SEARCH (search AAS and land-based NAS): Land-based search AAS and NAS may increase the number of search die rolls made during naval combat and modify submarine attack dice rolls.
C. COMBAT AIR PATROL (carrier-based NAS): Carrier-based NAS may assist in defending friendly naval units against enemy air attack.
D. AIR COVER (cover AAS, land-based NAS): Land-based cover AAS and NAS assist in defending friendly naval units against enemy air attack.
E. ATTACKING NAVAL UNITS AT SEA (attack AAS, NAS and kamikazes): Land-based attack AAS and NAS, carrier-based NAS and kamikazes may attack enemy naval units at sea.
F. ATTACKING NAVAL UNITS IN PORT (AAF, NAS and kamikazes): Land-based AAF, land- or carrier-based NAS and kamikazes may attack enemy naval units in port.
23.12 TIMING: The timing of the air activities set out above is detailed in the rules dealing with each activity.
23.13 CONVERSION OF AAF TO AAS:
23.131 WHEN CONVERSION OF AAF TO AAS REQUIRED: Each AAF is converted to three AAS immediately prior to engaging in any of the following activities:
A. Engaging in air combat in conjunction with friendly NAS or against an enemy force containing NAS.
B. Assisting in naval interception (spotting).
C. Providing air cover for friendly naval units.
D. Searching during naval combat or submarine attacks.
E. Attacking enemy naval units at sea.
23.132 CONVERSION RATIO: Each AAF is converted into:
A. One search AAS.
B. One cover AAS.
C. One attack AAS.
23.133 MECHANICS: When an AAF is converted to AAS, the AAF is replaced by three AAS (one AAS of each type). The AAF is placed in the designated area on the owning major power’s force pool chart, in order to ensure that the conversion of AAF to AAS and the subsequent conversion of AAS back to AAF does not result in the owning major power inadvertently having too few or too many AAF in play.
23.14 CONVERSION OF AAS TO AAF:
23.141 WHEN CONVERSION OF AAS TO AAF REQUIRED: AAS are converted back into AAF:
A. Immediately prior to engaging in any of the following activities. Only the army air units participating in the activity are converted.
·        Undertaking an air operation (17.23) other than those that may be performed by AAS (23.151), or continuing such an operation after its interruption by air combat. Inverted AAF that result from conversion may not undertake or continue an offensive or defensive mission.
·        Being engaged in air combat as a result of an enemy attack on their base, other than in conjunction with friendly NAS or by an enemy force containing NAS. AAS are never converted to AAF between rounds of air combat, even if all the NAS involved have been eliminated.
B. During the owning player’s unit construction phase. Every three unbuilt AAS are converted to one AAF. A remnant of two unbuilt AAS is converted to an AAF and a third AAS, which will be in play, is removed from any location selected by the owning player; a remnant of one unbuilt AAS is disregarded. Only unbuilt AAS are converted.
C. At the end of each player turn, all remaining AAS are converted back into AAF.
23.142 CONVERSION RATIO:
A. When AAS are converted back into AAF, two AAS are converted to one AAF, and remnants of one AAS are eliminated. Thus one AAS is eliminated; two, three or four AAS convert to one AAF; five, six or seven AAS convert to two AAF; and so on.
B. Unbuilt AAS are converted first. This determines the number of unbuilt AAF. AAS on the board are then converted, with a separate determination being made for each air base or mapboard box containing AAS.
C. Once conversion is completed, the number of AAF in play may not exceed the number of AAF in the owning major power’s force pool.
23.143 MECHANICS OF CONVERSION: When AAS are converted to AAF, every three AAS are replaced by one AAF. The AAF are taken from the designated area on the owning major power’s force pool chart (23.133) to ensure that the overall number of AAF in play remains correct.
EXAMPLE: Britain uses five AAF (15 AAS) in a naval battle and loses nine AAS, leaving two AAS in each of three hexes. At the end of the turn, the two AAS in each hex are converted to one AAF. Since this results in the British having one more AAF than their force pool limit permits, one of the AAF (in any of the three hexes) is removed from play.
23.144 INVERSION OF AAF: When three AAS are converted to an AAF, the AAF created is inverted unless it results from the combination of one uninverted AAS of each type (search, cover and attack). If one or more of the combining AAS is inverted, or if the AAF is not formed from one of each of the three types of AAS, the AAF is inverted. Inverted AAF may not continue their mission and instead return to base.
23.15 AAS OPERATIONS:
23.151 AAS ACTIVITES: The activities which may be performed by each type of AAS are restricted as set out in 23.11.
23.152 COUNTERAIRS:
A. AAF which counterair enemy forces containing NAS are first broken down into AAS (23.131A).
B. The AAS must then be used to counterair one or more enemy air bases, each of which must contain at least one NAS. No AAS may be withheld from counterair combat.
C. AAS from a single AAF may counterair more than one enemy air base, provided each enemy air base contains at least one NAS.
D. Surviving AAS are recombined into AAF and inverted once all counterair attacks in that phase are completed.
23.153 AAS IN AIR COMBAT: All three types of AAS engage in air combat with equal effectiveness.
23.154 LOSSES: Army air units which have broken down into AAS take losses as squadrons. AAS of the same nationality are considered to be of the same type when taking losses (19.65).
23.16 USE OF LAND-BASED AIR:
23.161 INTERACTING WITH MULTIPLE NAVAL ACTIVITIES: Uninverted land-based air squadrons in operational bases may search, provide air cover or attack naval units at sea. They may conduct these air activities in relation to any or all naval activities that pass within range of their base during one phase of a player turn (EXCEPTION: Land-based air squadrons that participate in a round of naval combat by searching, attacking or flying air cover may not conduct any activities in relation to a reinforcing naval force during its movement towards the naval combat hex immediately following the round, nor with any interceptions, counter-interceptions or naval combat resulting from such movement - 22.411B). A land-based air unit may perform only one such role in each round of naval combat or in each hex entered by a naval force outside naval combat.
EXAMPLE: An Italian TF invades Malta. Axis air units in Sicily are held back to cover the invasion. The British intercept with a TF from Gibraltar and a TF from Alexandria. A second Italian TF counter-intercepts the British TF intercepting from Gibraltar before it reaches the invading Italian TF.
The Axis air units in Sicily may attack the British TF intercepting from Alexandria (one sortie per hex), then the surviving Axis air units may participate in the naval combat between the British TF intercepting from Gibraltar and the counter-intercepting Italian TF; or vice versa, at the Axis player's option. The only restrictions on the use of the Axis air units are: a) they may only attack British naval units within range of their bases; and b) air squadrons eliminated in attacks on one British TF are removed from play and may not attack the other British TF.
23.162 RESTRICTIONS ON AIR MISSIONS: Land-based air squadrons already committed to an offensive or defensive air mission may not interact with naval activities. Similarly, once a land-based air squadron is committed to support or oppose a naval activity, it may not be used for an offensive or defensive air mission later in the phase.
23.163 USE OF AAS IN DIFFERENT HEXES PERMITTED: AAS may search, fly air cover and attack enemy naval units in different hexes, subject to range and other applicable restrictions. There is no requirement that the search, cover and attack components of an AAF be used in the same hex or at the same time.
23.164 INVERSION AT END OF PHASE: Land-based air squadrons are inverted at the end of the phase in which they search, provide air cover or attack naval units at sea.
EXAMPLE: German attack AAS attack a British TF which tries to intercept Axis sea supply to a German-controlled port in Britain. Germany then sea transports units into Britain. Any surviving German attack AAS may also attack any British TFs which try to intercept the German sea transport to Britain, as both the sea supply and the sea transport occur during the German movement phase. All the surviving German attack AAS are inverted at the end of the German movement phase and may not be used to attack British naval forces during the German combat phase.
23.165 NO BRP COST: Searching, providing air cover and attacking enemy naval units at sea are not offensive operations and do not require any expenditure of BRPs.
23.17 JETS: Jets convert to jet squadrons and back to jet factors, and incur losses, in the same manner as AAF.
23.18 AIR TRANSPORTS: Air transport factors convert to air transport squadrons and back to air transport factors, and incur losses, in the same manner as AAF. An air combat result which eliminates two or more air transport squadrons eliminates the air transport factor; any lesser air combat result other than “0” forces the air transport to discontinue its mission by inverting the air transport factor.

23.2 AIR COVER:
23.21 AIR COVER: Air cover may be flown by land-based air units to protect friendly naval units engaged in any naval activity. Air cover may not be provided for naval units in port. Air cover may be flown over:
A. NAVAL COMBAT: A specific combat group during naval combat.
B. OUTSIDE OF NAVAL COMBAT: An entire naval force if attacked by enemy air units independent of naval combat.
C. AGAINST KAMIKAZES: Air cover flown over a naval force which is attacked by kamikazes is assigned on a prorated basis to each combat group in the naval force, rounding up in favor of combat groups which are selected as kamikaze targets.
EXAMPLE: Seven American air squadrons fly air cover over an American naval force containing three TFs. Each TF becomes a combat group. The Japanese launch a kamikaze attack against one of the combat groups in the naval force (17.475A). Three air squadrons fly air cover over the attacked combat group and engage the attacking kamikazes; the other four air squadrons are considered to be flying air cover over the other two combat groups and do not participate in the defense of the attacked combat group.
23.22 AIR COVER AGAINST LAND-BASED AIR ATTACKS:
A. As a naval force enters each hex of its path while moving to its destination, the opposing player may attack that naval force with land-based air units and the defender may use some, all or none of his available eligible air units for air cover.
B. The decision to fly air cover outside of naval combat is made immediately after the opponent announces an air attack against a friendly naval force.
C. The defender is not required to commit his available air units to air cover against land-based air attacks before they are made, although he may not have used those air units for other purposes.
D. Once air combat is resolved, both sides’ surviving air units return to their bases and the naval force moves to the next hex along its previously announced path, unless it was destroyed or aborted its activity. The process in then repeated as the naval force enters each hex of its route.
23.23 AIR COVER DURING NAVAL COMBAT:
A. ASSIGNED BEFORE AIR STRIKES ANNOUNCED: Air cover during naval combat is assigned immediately after carrier-based naval air units are assigned to air strikes and combat air patrol (22.41D), before any air strikes are announced.
B. ROUND-BY-ROUND ASSIGNMENT: Each round, a player may use some, all or none of his available eligible land-based air units for air cover, regardless of how they were used in any previous round.
23.24 EFFECTS OF AIR COVER ON ATTACKING AIR UNITS: See 23.412.

23.3 COMBAT AIR PATROL:
23.31 COMBAT AIR PATROL: Combat air patrol may be flown by carrier-based naval air units over:
A. NAVAL COMBAT: Their own combat group during naval combat.
B. OUTSIDE OF NAVAL COMBAT: Their entire naval force if attacked by enemy air units independent of naval combat.
C. AGAINST KAMIKAZES: Naval air units in a naval force which is attacked by kamikazes may fly combat air patrol flown only over their own combat group (17.475E).
23.32 ONE-THIRD RESTRICTION: No more than one-third (round up) of the available carried-based NAS may be allocated to combat air patrol over their combat group (23.31A) or naval force (23.31B). This determination is made at the start of each round of naval combat or as each new hex is entered by a naval force.
EXAMPLE: A Japanese combat group contains four CVs, each of which has three NAS, for a total of 12 NAS. Four Japanese NAS may fly combat air patrol over the Japanese combat group in the first round of naval combat. If three of the Japanese NAS were eliminated in that combat round, either while defending against enemy air attacks or while attacking enemy air or naval units, the Japanese combat group would have nine NAS for the second combat round, of which three Japanese NAS could fly combat air patrol over the Japanese combat group.
23.33 COMBAT AIR PATROL AGAINST LAND-BASED AIR ATTACKS:
A. As a naval force enters each hex of its path while moving to its destination, the opposing player may attack that naval force with land-based air units and the defender may use some, all or none of his available eligible air units for combat air patrol
B. The decision to fly combat air patrol outside of naval combat is made immediately after the opponent announces an air attack against a friendly naval force.
C. The defender is not required to commit his available air units to combat air patrol against land-based air attacks before they are made, although he may not have used those air units for other purposes.
D. Once air combat is resolved, both sides’ surviving air units return to their bases and carriers and the naval force moves to the next hex along its previously announced path, unless it was destroyed or aborted its activity. The process in then repeated as the naval force enters each hex of its route.
23.34 COMBAT AIR PATROL DURING NAVAL COMBAT:
A. ASSIGNED BEFORE AIR STRIKES ANNOUNCED: Combat air patrol during naval combat is assigned at the same time as carrier-based naval air units are assigned to air strikes (22.41D), before any air strikes are announced.
B. ROUND-BY-ROUND ASSIGNMENT: Each round, a player may use some, all or none of his available eligible carrier-based naval air units for air cover, regardless of how they were used in any previous round.
23.35 CVEs: CVEs do not contribute to combat air patrol.
23.36 EFFECTS OF COMBAT AIR PATROL ON ATTACKING AIR UNITS: See 23.412.

23.4 RESOLVING AIR ATTACKS ON NAVAL UNITS:
23.41 The following mechanisms are used to resolve air attacks on naval units.
23.411 EFFECT OF DEFENDING AIR - PORTS:
23.4111 COUNTERAIR OPTIONAL: When air units attack an enemy port which contains both air and naval units, the attacker has the option of counterairing the defending air units with some, all or none of his attacking air factors. Carrier-based naval air units concealed by a TF marker are revealed when the attacker announces his attack on the carriers’ base.
23.4112 ALL ATTACKING AIR UNITS COUNTERAIR: If all the attacking air units counterair, the attack is resolved solely as a counterair attack (18.52), with each side making one air combat dice roll to resolve that round of air combat. No air defense dice roll is made for the base and no naval units in the target hex may be attacked in that combat round.
23.4113 SOME ATTACKING AIR UNITS COUNTERAIR: If some of the attacking air units carry out a counterair attack and the remainder attack the naval units in the enemy base, one round of air combat is resolved between the attacking and defending air units engaged in counterair combat. Attacking air units which engaged in counterair combat may not attack naval units in the enemy base in that combat round, regardless of the result of the counterair combat. Some or all of the remaining attacking air units may be able to carry out their attack on the naval units in the enemy base, depending on the defender’s air combat result (23.4115B).
23.4114 NO ATTACKING AIR UNITS COUNTERAIR: If all of the attacking air units attempt to attack the naval units in the enemy base, ignoring the defending air units, all uninverted defending air units make one air attack dice roll against the attacking air units (23.4115B).
23.4115 EFFECTS OF AIR COMBAT:
A. ATTACKER'S AIR COMBAT RESULT: Defending air units forced to abort by the attacker's air combat dice roll participate in subsequent rounds of combat against their hex. Defending air units forced to abort in the final round of attack against their hex are inverted for the remainder of the attacker's player turn (18.526).
B. DEFENDER’S AIR COMBAT RESULT: Attacking air units which are eliminated or forced to abort by the defender’s air combat dice roll may not attack the naval units in the enemy base in that round. If the effects of the defender’s air combat result exceed the number of attacking air units which counteraired the defending air units, the excess is taken from the air units which would have otherwise attacked the defender’s naval units. This will always occur if the attacker did not counterair the defender, as the defender’s uninverted air units still make an air combat dice roll. Apart from the defender’s air combat result, defending air has no effect on air attacks on naval units in port.
EXAMPLE: Fifteen American NAS attack a Japanese port containing two uninverted AAF, six uninverted NAS and eight factors of light ships.
The American player decides to counterair the Japanese air units in the first round of his attack. Counterair combat is resolved between the fifteen attacking American NAS and the six Japanese NAS and the six Japanese AAS (two search AAS, two cover AAS and two attack AAS - 23.131). The American air combat result is a “6/6”, which eliminates two Japanese NAS and four Japanese AAS (one AAS of each type and a fourth AAS of the Japanese player’s choosing). The Japanese air combat result is a “4/4”, which eliminates four American NAS. The aborted air squadrons are irrelevant.
In the second round, four of the remaining eleven American NAS counterair the remaining two Japanese AAS and four Japanese NAS, while the other seven American NAS attack the Japanese light ships. The American air combat result is a “2/2”, which eliminates two Japanese air squadrons and aborts two others. The six Japanese air squadrons achieve a “2/3” air combat result, which eliminates two of the counterairing American NAS, aborts the other two, and aborts one of the American NAS which was going to attack the Japanese naval units.
This leaves six American NAS to attack the Japanese naval units. After the Japanese air defense dice roll is made, the American player resolves his attack, then decides whether to make a third rounds of attacks. If he doesn’t, the Japanese would end the combat with one inverted AAS, one inverted NAS and two uninverted NAS, plus any naval units which survived the American attack.
23.4116 NEARBY DEFENDING AIR UNITS IGNORED: Defending air units based in hexes other than the hex under air attack may not assist in the air defense of that base. The attacker need only concern himself with air units based in the hex which is under attack.
23.4117 INVERTED AIR UNITS: Inverted air units do not make an air combat dice roll against the attacker’s air units unless the attacker elects to counterair them.
23.412 EFFECT OF DEFENDING AIR - AT SEA:
23.4121 AIR COMBAT WITH ATTACKING AIR UNITS:
A. DEFENDER’S PARTICIPATION OPTIONAL:
·       Air squadrons flying air cover or combat air patrol over a friendly naval force which is under air attack may engage in air combat with an equal number of attacking air squadrons.
·        Some or all of the defending air units flying air cover or combat air patrol over attacked naval units may be withheld from air combat. This is announced before the attacker chooses which air factors to assign to air combat.
·       Defending air units which do not engage the attacking air units do not incur casualties from any other air combat which may occur and have no effect on any ensuing air attacks on the defender’s naval units in that combat round.
B. ATTACKER’S PARTICIPATION MANDATORY:
·       If defending air units flying air cover or combat air patrol over an attacked naval force or combat group elect to engage attacking air units, air combat is resolved between the defending air squadrons and an equal number of attacking air squadrons.
·       If there are fewer attacking air squadrons than covering air squadrons, all the attacking air squadrons must engage in air combat with the defending air units.
·       If there are more attacking air squadrons than covering air squadrons, the attacker decides which of his air squadrons will engage in air combat with the defending air units. The attacker may not commit more air squadrons to air combat than the defender.

The defender determines how many attacking air squadrons he engages in air combat (the same number of squadrons as are flying air cover, unless there are more air squadrons flying air cover than are attacking or the defender wishes to withhold air units from combat). The attacker then decides which of his attacking air squadrons engage in air combat with the air squadrons flying air cover.

Air Defense Table - 23.42
Air	Dice Roll
DF	2	3	4	5	6	7	8	9	10	11	12+
1	0	0	0	0	0	0/1	0/1	1/0	1/0	1/1	1/1
2	0	0	0/1	0/1	1/0	1/0	1/1	1/1	1/2	1/2	2/1
3	0/1	0/1	1/0	1/0	1/1	1/1	1/2	1/2	2/1	2/1	2/2
4	1/0	1/0	1/1	1/1	1/2	1/2	2/1	2/1	2/2	2/2	2/3
5	1/0	1/1	1/1	1/2	1/2	2/1	2/1	2/2	2/2	2/3	2/3
6	1/1	1/1	1/2	1/2	2/1	2/1	2/2	2/2	2/3	2/3	3/2
7	1/1	1/2	1/2	2/1	2/1	2/2	2/2	2/3	2/3	3/2	3/2
8	1/2	1/2	2/1	2/1	2/2	2/2	2/3	2/3	3/2	3/2	3/3
9	1/2	2/1	2/1	2/2	2/2	2/3	2/3	3/2	3/2	3/3	3/3
10	2/1	2/1	2/2	2/2	2/3	2/3	3/2	3/2	3/3	3/3	3/4
Air Defense Level
+1	for every ten naval factors, including damaged naval factors (round fractions up). Ships sunk in port, submarines and transports are not counted. Each CVE is worth three naval factors.
+1	each air defense research result
+1	each flak factor, airbase counter, objective or anchor symbol
+2	each city or port
+1	each fortification level (+1 for a fortification; +2 for a fortress; beach defenses have no effect on air defense levels)
+1	for each five-factor battleship in the attacked naval force
-1	if the attacker achieves a surprise level of 2 or greater
If the air defense level is more than 10, the result is determined by consulting the "10" row and whatever other row is required to equal the total air defense level.
Results: The number before the slash is the number of attacking air squadrons or factors which are eliminated. The number after the slash is the number of attacking air squadrons or factors which abort their mission and return to base (EXCEPTIONS: Carrier-based NAS attacking ships at sea do not abort and ignore the number after the slash - 23.424). Air units which abort may take part in future air sorties during the current air attack.

23.421 AIR DEFENSE LEVEL OF NAVAL FORCES: The defensive strength of a naval force is determined as indicated on the Air Defense Table:
A. All attacked naval units, including damaged naval units and destroyers which are carrying cargo, are counted in determining the air defense level (EXCEPTIONS: 23.421C-E).
B. Each CVE is considered to be worth three naval factors for the purposes of air defense.

The air defense value of a CVE is three times that of other naval units to reflect its intrinsic NAS, which are not represented in the game.

C. Ships sunk in port, submarines and transports are not counted.
D. A naval force only makes an air defense roll if its air defense level is one or more. A naval force which would otherwise be unable to make an air defense roll, such as an unprotected sea supply line, makes an air defense roll if the owning player has achieved at least one air defense research result (EXCEPTION: Attacked submarines never make an air defense roll).
23.422 COMBAT GROUPS: Each combat group defends separately when attacked during naval combat or by kamikazes (17.475E).
23.423 PORTS: If the attacked naval force is in port, the air defense level is supplemented by the port defenses. Naval units attacked at sea do not receive the benefit of port defenses, even if they are moving through a hex which contains a port.
23.424 RESULTS: The number before the “/” indicates the number of attacking air units which are eliminated (normally squadrons; AAF for army air units attacking naval units in port). The number after the “/” indicates the number of attacking air squadrons or factors which must abort (EXCEPTIONS: Carrier-based NAS attacking ships at sea do not abort). Air units which abort return to their base without loss and do not take part in that air sortie, but may attack in subsequent sorties. Losses to mixed forces are apportioned as per 19.6.
23.425 NO OPTION TO CALL OFF ATTACK AFTER AIR COMBAT: Air units which are not eliminated or forced to abort by air combat must undergo an air defense dice roll. They may not abort.
23.426 CONTENTS OF TARGET REVEALED: The precise contents of a targeted enemy combat group (or the entire naval force for naval units not participating in naval combat) are revealed to the attacker if at least one attacking air factor survived the air defense dice roll without being eliminated or forced to abort.
23.43 TARGET SELECTION BY ATTACKING AIR UNITS: Once the air defense dice roll is made and the results implemented, the attacker selects targets for his attacking air units (EXCEPTION: Kamikazes select their targets randomly - 17.475F).
A. NAMED SHIPS: Named ships may be targeted separately by attacking air units.
B. LIGHT SHIPS: Light ships are attacked as a group. For the effect of air attacks on destroyers and transports carrying cargo, see 20.58B and 20.59.
C. Submarines may be attacked by air only if they remain on patrol during the opposing player turn (21.4184C).
D. Naval units undergoing repair or construction on a Naval Construction Chart may only be attacked by strategic bombing (26.31H). Damaged naval units in the “Waiting for Repair” box of a Naval Construction Chart are subject to normal air attack.
23.44 AIR ATTACK DICE ROLLS: After assigning his attacking air to specific targets, the attacker rolls two dice for each target and consults the Naval Attack Table. Only those air units which have not been eliminated or aborted are taken into account when making the air attack dice roll.

Naval Attack Table - 20.51, 22.55, 23.44
AS	FF	Dice Roll
AS	FF	2	3	4	5	6	7	8	9	10	11	12+
1	1-2	0	0	0	0	1	1	1	1	2	2	2
-	3-4	0	0	0	1	1	1	1	2	2	2	3
2	5-6	0	0	1	1	1	1	2	2	2	3	3
3	7-9	1	1	1	1	2	2	2	3	3	3	4
4	10-12	1	1	2	2	2	3	3	3	4	4	5
5	13-15	2	2	2	3	3	3	4	4	5	5	6
6	16-18	2	2	3	3	3	4	4	5	5	6	6
7	19-21	2	3	3	3	4	4	5	5	6	6	7
8	22-24	3	3	3	4	4	5	5	6	6	7	7
9	25-27	3	3	4	4	5	5	6	6	7	7	8
10	28-30	3	4	4	5	5	6	6	7	7	8	8
11	31-33	4	4	5	5	6	6	7	7	8	8	9
12	34-36	4	5	5	6	6	7	7	8	8	9	9
13	37-39	5	5	6	6	7	7	8	8	9	9	10
14	40-42	5	6	6	7	7	8	8	9	9	10	10
15	43-45	6	6	7	7	8	8	9	9	10	10	11
16	46-48	6	7	7	8	8	9	9	10	10	11	11
17	49-51	7	7	8	8	9	9	10	10	11	11	12
18	52-54	7	8	8	9	9	10	10	11	11	12	12
19	55-57	8	8	9	9	10	10	11	11	12	12	13
20	58-60	8	9	9	10	10	11	11	12	12	13	13
Modifiers - Air Attacks on Naval Units +# attacker’s Air Nationality DRM -# defender's Naval Nationality DRM +1 if the attacker achieves a surprise level of 3 or greater
Modifiers - Fleet Attacks on Naval Units +/-# Naval Nationality DRMs (22.552A) +/-1 If one of the combat groups involved is carrying out a naval activity which reduces its effectiveness (22.552B)
If more than 20 air squadrons engage in combat, the result is deter-mined by consulting the "20" row and whatever other row is required to equal the total number of air squadrons engaged. If more than 60 fleet factors engage in combat, the result is determined by consulting the "58-60" row and whatever other row is required to equal the total number of fleet factors engaged.
Results Named ships and cruisers: A named ship or cruiser is damaged if it incurs a naval attack effect one less than its size in factors and is sunk if it incurs a naval attack effect equal to or greater than its size in factors. Cruiser groups: If a group of light ships consisting only of cruisers incurs an odd number of hits, the odd hit damages one cruiser. One-factor naval units: If a group of ships consists only of destroyers, CVEs, transports or a combination of the three, each hit sinks a destroyer, CVE, or transport factor. Mixed light forces: Naval attack effects incurred by a light force consisting of both cruisers and one-factor naval units are distributed evenly between the cruisers and one-factor naval units, subject to the proviso that the number of one-factor ship factors sunk may not exceed the number of cruiser factors sunk until all the cruisers in the force are sunk (20.551).

23.441 MODIFIERS: Air attack dice rolls against naval units are subject to the following modifiers:
A. +/-# attacker’s Air Nationality DRM (19.31A).

Air Nationality Chart - 19.31A, 23.441A
DRM	Nationality
2	Germany, Japan, United States, Britain, Finland, Sweden, Australia
1	Italy, Russia, France
0	All minor countries except Finland, Sweden and Australia
Modifiers
+1	Elite Japanese naval air
+1	Defending interceptors
-1	British naval air
-1	Air units subject to a winter effect of 8 or more
-1	Air units in partial supply or subject to air oil effects

B. +/-# defender’s Naval Nationality DRM (22.552A). A positive Naval Nationality DRM reduces the air attack dice roll; a negative Naval Nationality DRM increases the air attack dice roll .

Naval Nationality Chart - 22.552A, 23.441B
DRM	Nationality
3	Germany, Japan
2	Britain, United States, Sweden, Australia
1	Italy, France
0	Russia, Greece, Rumania, Spain, Turkey, Dutch East Indies
Modifiers
+1	Five-factor battleships
-2	Japanese and American CVBs, CVs, CVLs; all CVEs
-1	German, Italian and British CVLs
-1	Naval units in partial supply or subject to naval oil effects.
Explanation: When fleets with different DRMs engage in fleet combat, the two DRMs are compared. The higher ranking side adds the difference to its fleet combat dice roll, and the lower ranked side subtracts the difference from its fleet combat dice roll. Air attack dice rolls against naval units are reduced by the DRM of the attacked naval units.