The type of ships you could use. Including the Ship Of The Line, EITC Trader (Like the Black Pearl) and British Trader (Like the Queen Anne's Revenge)
This is a fun way to have a ship of your own design. It is much like Island Owning in how it is built. You go to any Shipwright, and click a button entitled "Custom Ship" You then buy a type of ship. Third, you customize it with colors, sails, laterns, etc. It's a great way to make new ship types.
Each island offers different types of custom items, sails, type of wood, the wheel, everything.
Also, there are cabins that the crew and captain can stay in, those as well can be customized. The more you put into the cabins, the more gold you must pay.
Ships to buy are: Light Sloop, Light Galleon, Light Frigate, Sloop, Galleon, Frigate, War Sloop, War Galleon, War
Adding a crows nest is one thing you could do.
Frigate, Ship Of The Line, EITC Trader, and British Trader.