Combat/Opening Anti-Submarine Warfare

Introduction

During the opening phases of combat, ships which meet certain requirements are able to perform opening ASW attacks. These attacks are valuable because they have the opportunity to sink submarines before they get the chance to perform opening torpedoes.

Overview

1. All ships with an ASW   stat are capable of performing OASW.

  • Theoretically any ship capable of ASW is able to perform OASW but no equipment exists that allows normal CVL, CAV and BBV to hit the 100 ASW threshold.

2. Upgrades to ASW equipment are not counted towards the thresholds for triggering OASW.

3. OASW attacks are performed in range order.

  • Attacks from ships with the same range are random.

4. Damage is calculated the same way as normal ASW.

5. You can modernise a ship's ASW using destroyer escorts. Please see Modernization for more details.


Trigger Requirements

Ship Requirement
All ASW capable ships
  • ASW ≥ 100
  • Is equipped with  
Destroyer Escorts

Either:

  • ASW ≥ 60 with  
  • ASW ≥ 75 with equipment that has 4≤ ASW
Isuzu Kai Ni
Tatsuta Kai Ni
Jervis Kai
Janus Kai
Samuel B. Roberts Kai
Fletcher
Johnston
Yuubari Kai Ni D
  • Default OASW regardless of ASW stat or equipment.
Taiyou
Shinyou
Gambier Bay
Zuihou Kai Ni B

Have both:

  • ASW ≥ 50
  •  
  • At least 1   with ASW ≥ 7,  , or  

Have both:

  • ASW ≥ 65
  • At least 1   with ASW ≥ 7,  , or  

Have both:

  • ASW ≥ 100
  •  
  • At least 1   or   with an ASW stat.
Taiyou Kai/Kai Ni
Shinyou Kai Kai Ni
  • ASW ≥ 65
Light Carriers (Except Suzuya and Kumano)
  • ASW ≥ 50
  •   (Large SONAR only)
  • At least 1   with ASW ≥ 7,  , or  
Hyuuga Kai Ni

Either:

Minimum OASW Level

The minimum level for OASW can be calculated using:


[math]\displaystyle{ \text{Level}_\text{min} = \bigl\lceil \left( \left(\text{OASW}-\text{ASW}_\text{equip} \right) - \text{OASW}_\text{min} \right) \times \frac{99}{\text{OASW}_\text{max}-\text{OASW}_\text{min}} \bigr\rceil }[/math]

  • [math]\displaystyle{ \text{OASW}_\text{min} }[/math] is the minimum ASW of the ship as noted in the tables below.
  • [math]\displaystyle{ \text{OASW}_\text{max} }[/math] is the maximum ASW of the ship as noted in the tables below.
  • [math]\displaystyle{ \text{ASW}_\text{equip} }[/math] is the total base ASW provided by equipment.
  • [math]\displaystyle{ \text{OASW} }[/math] is the relevant OASW threshold.
    • [math]\displaystyle{ 60 }[/math] for DEs with sonars.
    • [math]\displaystyle{ 75 }[/math] for DEs without sonars and ASW equipment that have ASW ≥ 4.
    • [math]\displaystyle{ 65 }[/math] for CVLs with ASW > 7 planes OR Taiyou/Shinyou Kai/Kai Ni
    • [math]\displaystyle{ 100 }[/math] for all other ships.


Minimum OASW Chart

The following apply to the tables below:

  • Only easily obtainable equipment combinations are shown.
  • The equipment abbreviations are:
  • Ships with default ASW as detailed in the section above aren't listed.
  • Numbers in brackets are the total ASW of the equipment setup.
  • Only the top remodel is applicable unless otherwise stated.
  • If you require minimum OASW levels for remodels or equipment combinations that aren't listed, you can use the formula above and minimum and maximum ASW stats on the ship girl pages.

OASW Tables

All ships are presumed to be of the highest possible remodel unless otherwise stated

Destroyers
Ship Min ASW Max ASW
3 Slots 2 Slots 1 Slot
T4S/T4S/T4S
(36)
T4S/T4S/T3CP
(32)
T3S/T3S/T3S
(30)
T3S/T3S/T3DCP
(28)
T3S/T3DCP/T2DC
(25)
T4S/T4S
(24)
T3S/T3S
T4S/T3DCP
(20)
T3S/T3DCP
(18)
T4S
(12)
T3S
(10)
Asashio K2 D 45 89 85 85 85 85 85 85 85 85 97 102
Urakaze D 45 88 69 69 69 69 70 72 81 86 99 104
Tanikaze D 44 86 70 70 70 70 74 76 85 90 104 109
Maestrale
Libeccio
40 80 60 70 75 80 87 90 99 104 119 124
Grecale 38 79 63 73 78 83 90 92 102 107 121 126
Shiratsuyu K2 30 83 77 77 77 79 85 86 94 98 109 113
Arare K2 33 81 64 73 77 81 87 89 97 102 114 118
Umikaze K2 28 82 82 82 82 82 87 88 96 99 110 114
Satsuki K2 30 81 75 75 78 82 88 90 98 101 113 117
Fumizuki K2 30 81 77 77 78 82 88 90 98 101 113 117
Asashimo 35 79 66 75 79 84 90 93 102 106 120 124
Shikinami K2 30 79 69 77 81 85 91 93 102 106 118 122
Okinami K2 29 79 79 79 82 86 92 94 101 105 117 121
Kazagumo K2 29 78 75 79 83 87 93 95 104 108 120 124
Verniy 30 77 72 81 85 89 95 97 106 110 123 127
Yuugumo K2 30 77 75 81 85 89 95 97 106 110 123 127
Tashkent 40 73 72 84 90 96 105 108 120 126 144 150
Murasame K2 29 77 73 81 85 89 95 97 106 110 122 126
Shigure K2 31 76 73 82 86 91 97 99 108 113 126 130
Ushio K2 32 75 74 83 88 93 99 102 111 116 129 134
Hamakaze B K 32 72 80 90 95 99 107 109 119 124 139 144
Makigumo K2
Kishinami
Akizuki
Teruzuki
Hatsuzuki
30 72 81 90 95 99 107 109 118 123 137 142
Hatsushimo K2 28 72 81 90 95 99 106 108 117 122 135 140
Suzutsuki 28 71 83 93 97 102 109 111 120 125 139 143
Harukaze 22 72 84 92 96 99 105 107 115 119 131 135
Okinami 32 70 84 94 99 105 113 115 126 131 146 152
Kuroshio K2
Isokaze B K
31 70 84 94 99 105 112 115 125 130 145 150
Z1 Zwei
Z3 Zwei
37 69 84 96 103 109 118 121 134 140 158 164
Arashi 30 70 85 95 99 104 112 114 124 129 144 149
Kamikaze 24 70 87 95 99 104 110 112 121 125 138 143
Hatakaze 21 70 87 95 99 104 110 112 120 124 136 140
Hatsuharu K2
Yamakaze
30 69 87 97 102 107 115 117 127 132 148 153
Mutsuki K2
Murakumo K2
Yuudachi K2
28 69 87 97 102 107 114 116 126 131 145 150
Matsukaze 20 70 88 96 99 103 109 111 119 123 135 139
Kisaragi K2 27 69 88 97 102 107 114 116 125 130 144 149
Hayanami 26 69 88 97 102 106 113 116 125 129 143 148
Shiranui K2
Naganami K2
30 68 89 99 105 110 118 120 131 136 152 157
Kasumi K2/B
Nowaki
Hagikaze
Akishimo
28 68 90 99 104 109 117 119 129 134 149 154
Maikaze 27 68 90 99 104 109 116 119 128 133 148 153
Fubuki K2 26 68 90 99 104 109 116 118 128 132 147 151
Kagerou K2 30 67 91 102 108 113 121 124 134 140 156 161
Asakaze 18 68 92 99 103 107 113 115 123 127 139 143
Takanami
Hayashimo
Kiyoshimo
29 67 92 102 107 113 120 123 133 139 154 159
Oyashio 27 67 92 102 107 112 119 122 132 137 151 156
Akatsuki K2
Fujinami
28 66 94 105 110 115 123 126 136 141 157 162
Hamanami 28 65 97 108 113 118 126 129 140 145 161 166
Uzuki 21 65 97 106 111 115 122 124 133 138 151 156
Yamagumo
Hatsukaze
Akigumo
27 64 99 110 116 121 129 132 142 148 164 169
Ooshio K2
Tokitsukaze
26 64 99 110 115 120 128 131 141 146 162 167
Ayanami K2
Kawakaze K2
25 63 102 113 118 123 131 133 144 149 165 170
Minazuki 19 61 107 116 121 125 132 135 144 149 163 168
Michishio K2 26 60 111 123 129 134 143 146 158 164 - -
Yayoi
Nagatsuki
Kikuzuki
Mikazuki
Mochizuki
18 59 112 121 126 131 138 141 150 155 170 174
Asashio K2
Arashio K2
26 59 114 126 132 138 147 150 162 168 - -
All other destroyers 24 59 114 125 131 136 145 148 159 165 - -
Amatsukaze 28 59 115 128 135 141 151 154 167 173 - -
Yukikaze
Shimakaze
27 59 115 127 134 140 149 152 164 171 - -
Minegumo 24 58 117 129 134 140 149 152 164 169 - -
Light Cruisers
Ship Min ASW Max ASW
3 Slots 2 Slots 1 Slot
T4S/T4S/T4S
(36)
T4S/T4S/T3CP
(32)
T3S/T3S/T3S
(30)
T3S/T3S/T3DCP
(28)
T3S/T3DCP/T2DC
(25)
T4S/T4S
(24)
T3S/T3S
T4S/T3DCP
(20)
T3S/T3DCP
(18)
T4S
(12)
T3S
(10)
Kinu K2 49 86 75 75 75 75 75 75 83 89 105 110
Naka K2 48 85 48 54 59 65 73 75 86 91 108 113
Yura K2 49 83 77 77 77 77 77 79 91 97 114 120
Abukuma K2 48 82 75 75 75 75 79 82 94 99 117 123
Tama K2 43 83 70 70 70 72 80 82 92 97 112 117
Jintsuu K2 40 80 60 70 75 80 87 90 99 104 119 124
Sakawa 30 84 63 70 74 77 83 85 92 96 107 110
Kiso K2 32 82 64 72 76 80 86 88 96 99 111 115
Agano
Noshiro
Yahagi
26 82 68 75 78 82 87 89 96 99 110 114
Kitakami K2
Ooi K2
27 79 71 79 82 86 92 94 101 105 117 120
Kuma
Nagara
Natori
24 79 72 80 83 87 92 94 101 105 116 119
Sendai K2 38 74 72 83 88 94 102 105 116 121 138 143
Tenryuu K2 24 70 87 95 99 104 110 112 121 125 138 143
Yuubari 24 69 88 97 102 106 113 115 124 128 141 146
Yuubari Kai Ni 49 83 84 84 84 84 84 84 91 97 114 120
Yuubari Kai Ni Toku 27 70 86 95 99 104 111 113 123 127 141 146
Gotland 38 62 108 124 132 141 153 157 174 - - -
Giuseppe Garibaldi 25 60 111 122 128 133 142 145 156 162 - -
Duca degli Abruzzi 25 59 114 126 132 137 146 149 161 166 - -
Perth 20 55 125 136 142 148 156 159 170 - - -
De Ruyter 15 50 139 150 156 162 170 173 - - - -
Ooyodo 0 39 163 173 - - - - - - - -
Katori 22 62 103 114 119 124 132 134 144 149 164 169
Kashima 24 69 88 96 102 106 113 115 124 128 141 146
4-Slot Destroyer/Light Cruiser
Ship Min ASW Max ASW
4 Slots
T4S/T4S/T4S/T3DCP
(44)
T3S/T3S/T3S/T3DCP
(38)
T3S/T3S/T3DCP/T2DC
(35)
Tashkent 40 73 50 66 75
Yuubari 24 69 71 84 91
Yuubari Kai Ni 49 83 84 84 84
Yuubari Kai Ni Toku 27 70 86 86 88
Gotland 38 62 75 99 112
Giuseppe Garibaldi 25 60 88 105 114
Duca degli Abruzzi 25 59 91 108 117
Ooyodo 0 39 143 158 165
Katori 22 62 85 158 107
Kashima 24 69 62 84 91
Destroyer Escorts[1]
Ship Min ASW Max ASW
2 Slots 1 Slot
T4S/T4S
(24)
T3S/T3S
T4S/T3DCP
(20)
T3S/T3DCP
(18)
T4S
(12)
T3S
(10)
Shimushu 32 72 10 20 25 40 45
Kunashiri 31 70 13 23 28 44 49
Ishigaki 32 75 10 19 24 37 42
Hachijou 31 72 13 22 27 42 46
Etorofu
Matsuwa
Tsushima
Fukae
35 72 3 14 19 35 41
Sado 36 73 1 11 17 33 38
Mikura
Hiburi
40 78 1 1 6 21 27
Daitou 40 77 1 1 6 22 27
  1. Only values for base remodels are calculated because all DEs are capable of 1-slot OASW on kai.
Light Carriers[1]
Ship Min ASW Max ASW
931/931/931
(21)
931/931
(14)
931/
(7)
Taiyou 35 69 30 47 67
Shinyou 36 60 33 62 91
Zuihou K2 B 32 48 75 118 161
Gambier Bay 30 68 45 55 73
  1. Only values for base remodels are calculated for Taiyou and Shinyou because they are capable of 1-slot OASW on Kai and K2.

See Also