Bucket icon
  • Docking (repair) will restore your ships to full health, at the expense of fuel and steel.
  • While under repairs, it is not possible to cancel repairs or modify equipments or perform other activities like modernization.
  • Larger and higher-level ships take more time to repair. But it is possible to repair a ship instantly by using fast repair material (bucket).
  • Buckets DO NOT offset the resource requirements (fuel & steel) needed for repairs. The needed resources will still be consumed regardless.
  • If a ship ends repair with 39 morale or less, it will be reset to 40 upon finishing.
  • You can shave off the last minute of repair time by switching to the docking screen when a ship has less than one minute of repair time to go.
  • You start the game with two repair dock slots—you can pay money (DMM points) to buy keys in the shop and expand to 3 or 4 slots.
  • To use buckets to instantly finish repairs use the green button (shown below) or activate the slider on the repair confirmation window (shown on the side).

Repair time

 
Confirmation window for repairs

[math]\displaystyle{ \text {Total repair time} = \text {HP loss} \times \text {base repair time} \times \text {ship type multiplier} + \text {30 seconds} }[/math] [math]\displaystyle{ \text {Base repair time} = \text {Level} \times 10 \text {(if Level } \le \text {11); } \text {Level} \times 5 + floor (\sqrt {Level - 11}) \times 10 + 50 \text { (if Level } \ge \text {12)} }[/math]

Ship Type Multiplier
Battleships, Aviation Battleships, Aircraft Carriers, Repair Ships 2
Heavy Cruisers, Aviation Cruisers, Fast Battleships, Light Aircraft Carriers, Submarine Tenders 1.5
Light Cruisers, Destroyers, Submarine Aircraft Carriers, Seaplane Tenders, Amphibious Assault Ships, Torpedo Cruisers 1
Submarines 0.5

Repair cost

[math]\displaystyle{ \text {Fuel cost} = floor(\text {Base fuel cost} \times \text {HP loss} \times 0.032) }[/math]
[math]\displaystyle{ \text {Steel cost} = floor\text {Base fuel cost} \times \text {HP loss} \times 0.06), }[/math] where base fuel cost is the amount of fuel needed to resupply that ship from 0 to full. The cost is rounded down when using dry docks, so most destroyers and submarines with only 1 HP loss can be repaired for free. This is an incentive (a very minor one) to keep your ships repaired via dry docks.

Ship Repair Cost per HP
(assuming max remodel level)
Type Class Cost
   
Destroyers Shimakaze
Amatsukaze
Akitsuki
Z1-class
0.64 1.2
Others 0.48 0.9
Light Cruisers Ooyodo 1.12 2.1
Agano-class 0.96 1.8
Others 0.8 1.5
Torpedo Cruisers (all) 0.8 1.5
Heavy Cruisers Furutaka-class
Aoba-class
1.12 2.1
Tone-class Kai
Myoukou-class Kai Ni
1.44 2.7
Prinz Eugen 1.76 3.3
Others 1.28 2.4
Aviation Cruisers (all) 1.6 3
Battleships Ise-class
Fusou-class
2.72 5.1
Nagato-class
Kongou-class
3.2 6
Bismarck zwei 3.36 6.3
Bismarck drei 3.52 6.6
Vittorio Veneto-class 4.16 7.8
Yamato-class 8 15
Aviation Battleships Ise-class Kai 3.04 5.7
Fusou-class Kai Ni 3.36 6.3
Submarines (all) 0.3 0.8
Submarine Aircraft Carriers I-401 0.8 1.5
Others 0.32 0.6
Seaplane Tenders Chitose-class 1.12 2.1
Akitsushima 1.6 3
Light Aircraft Carriers Houshou 0.96 1.8
Ryuuhou 1.12 2.1
Shouhou-class
Ryuujou
1.28 2.4
Chitose-class Carrier
Hiyou-class
1.44 2.7
Aircraft Carriers Unryuu-class 1.6 3
Shoukaku-class 2.08 3.9
Hiryuu
Souryuu
2.24 4.2
Akagi 2.4 4.5
Kaga 2.56 4.8
Taihou 2.88 5.4
Submarine Tenders Taigei 1.12 2.1
Amphibious Assault Ships Akitsumaru 1.44 2.7
Repair Ships Akashi 1.7 3.3
Training Cruisers Katori 1.12 2.1
Collaboration Ships SS Iona 4.8 9
CA Takao 5.6 10.5
BB Haruna 6.4 12
Type Class    

Full list of rounded ship class cost: Wikiwiki

Examples

Level 67 Kongou with 41/75 HP (34 damage) will have:

  • Repair time:
    • [math]\displaystyle{ 34 \times \text{455 seconds} \times 1.5 + \text{30 seconds} = \text{23235 seconds or 6:27:15} }[/math]
  • Resource costs:
    • [math]\displaystyle{ 90 \times 34 \times 0.06 = \text{183 steel} }[/math]
    • [math]\displaystyle{ 90 \times 34 \times 0.032 = \text{97 fuel} }[/math]

Level 150 Musashi with 1/106 HP (105 damage) will have

  • Repair time:
    • [math]\displaystyle{ 105 \times \text{915 seconds} \times 2.0 + \text{30 seconds} = \text{192180 seconds or 53:23:00} }[/math]
  • Resource costs:
    • [math]\displaystyle{ 250 \times 105 \times 0.06 = \text{1575 steel} }[/math]
    • [math]\displaystyle{ 250 \times 105 \times 0.032 = \text{840 fuel} }[/math]
  • This is the highest in the game currently.