Docking

Docking (repair) can restore your ships to full health, which costs you fuel and steel.
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).
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.

Repair time

[math]\displaystyle{ \text {Total repair time} = \text {HP loss} \times \text {base repair time} \times \text {ship type} + \text {30 seconds} }[/math]

Ship Type	Multiplier
Slow battleship, Aircraft carrier	2
Heavy Cruiser, Battlecruiser/fast battleship, Light aircraft carrier	1.5
Light Cruiser, Destroyer, Aircraft-carrying submarine, Seaplane tender	1
Submarine	0.5

Battlecruiser/fast battleship: Kongou-class
Aircraft-carrying submarine: I-58 Kai, I-19 Kai, I-8 Kai
These are assumed times based on calculations and rounding.
Represented as [minutes]:[seconds]

Lv	Base repair time
1	0:10
2	0:20
3	0:30
4	0:40
5	0:50
6	1:00
7	1:10
8	1:20
9	1:30
10	1:40
11	1:50
12	2:00
13	2:05
14	2:10
15	2:25
16	2:30
17	2:35
18	2:40
19	2:45
20	3:00

Lv	Base repair time
21	3:05
22	3:10
23	3:15
24	3:20
25	3:25
26	3:30
27	3:45
28	3:50
29	3:55
30	4:00
31	4:05
32	4:10
33	4:15
34	4:20
35	4:25
36	4:40
37	4:45
38	4:50
39	4:55
40	5:00

Lv	Base repair time
41	5:05
42	5:10
43	5:15
44	5:20
45	5:25
46	5:30
47	5:45
48	5:50
49	5:55
50	6:00
51	6:05
52	6:10
53	6:15
54	6:20
55	6:25
56	6:30
57	6:35
58	6:40
59	6:45
60	7:00

Lv	Base repair time
61	7:05
62	7:10
63	7:15
64	7:20
65	7:25
66	7:30
67	7:35
68	7:40
69	7:45
70	7:50
71	7:55
72	8:00
73	8:05
74	8:10
75	8:25
76	8:30
77	8:35
78	8:40
79	8:45
80	8:50

Lv	Base repair time
81	8:55
82	9:00
83	9:05
84	9:10
85	9:15
86	9:20
87	9:25
88	9:30
89	9:35
90	9:40
91	9:45
92	10:00
93	10:05
94	10:10
95	10:15
96	10:20
97	10:25
98	10:30
99	10:35
100

Repair cost

See ship list or remodeled ship list for their base fuel cost.

[math]\displaystyle{ \text {Steel} = \text {Base fuel cost} \times \text {HP loss} \times 0.06 }[/math]
[math]\displaystyle{ \text {Fuel} = \text {Base fuel cost} \times \text {HP loss} \times 0.032 }[/math]

Example

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]