You can upgrade ships through modernization, thereby increasing their firepower, armor, anti-air and/or torpedo attack stats. It is also a good way to get rid of unwanted ships filling up your docks.
First, pick the ship you want to upgrade on the Refit screen, click on the green button on the left, and choose 1 to 5 ships to "merge" into your ship. This process will destroy them, so make sure you do not pick any you want to keep.
Note
You will lose all modernization upgrades after remodeling. Don't let it discourage you from modernizing your girls, unless they are close to remodel level.
A consumed ship's equipments get wasted, You will not retain any equipment still equipped on the consumed ship. Remember to remove any valuable equipment the consumable ship might possibly have. Also, stock equipment can be scrapped for small amounts of resources, though this is most likely not worth the effort.
There is a maximum cap for upgrades; you can view this number on one of the tables here or on the ship's page (it is the number in parentheses).
Modernization can fail with +1 only, see the graph below for details (0 will give you the penguin failure screen, all other results will display as the success message).
Input
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Success
1
2
3
5
6
7
8
9
11
12
13
14
15
17
Fail
0
1
2
2
3
3
4
5
5
6
6
7
8
8
Note: The table does not apply to Luck modernization.
The chance of success is 50% for each stat you're trying to boost with Modernization. I.E. you can attempt to Modernize for +15 firepower +15 armor, but end up with only +15 firepower +8 armor as a result.
Luck
Following the December 2013 update, Maruyu can be used as Modernization material for +1.2 luck (+1.6 luck if she is remodeled to Maruyu Kai). The result will be rounded down after adding a random number below 1. You can still increase a maxed-out ship's luck through modernization. Luck does not reset upon remodeling.
Maruyu
1
2
3
4
5
Expected
1.2
2.4
3.6
4.8
6.0
Success
2
3
4
5
6
Fail
1
2
3
4
Chance
20%
40%
60%
80%
N/A
Maruyu Kai
1
2
3
4
5
Expected
1.6
3.2
4.8
6.4
8.0
Success
2
4
5
7
8
Fail
1
3
4
6
Chance
60%
20%
80%
40%
N/A
Note: Although the indicator will display +6 luck for 5 Maruyu Kai before modernzation, it is guaranteed to award +8 luck once carried out.
Ships
All ships will provide a fixed input for modernization.