Warship

The Warship icon is used to equip and upgrade ships that you have collected.

Warships give your characters bonus stats for Pirate War, Arena, and Faction War.

Here is where you can choose which Warships you will use to increase your bonus stats.

The Synthesize page is used to upgrade your ship with the use of ship souls.

The rates per level are 1:3 so:

1:3 
3:9 
9:27
27:81
81:243
243:729
729:2,187
2,187: 6,561
6,561:19,683
19,683:59,049

So you'll need 59,049 level 1 ships to make 1 Level 10 Ship

Here are all the ships that can be obtained in the game:

Their bonuses increase by a certain amount per ship level.