The HMS Prince
This Legendary ship is one that you can unlock by taking over the Navassa fort in the southeast waters. The fort can be a bit of a pain, but is much easier than the opponent it unlocks. The HMS Prince has a mean broadside attack with its cannons like all the Legendary ships, but it also has one other attack it abuses and that’s its mortars. If you are anywhere beside the craft or in front of it, it will constantly assault you with mortar attacks.
It can be a huge pain to try and dodge the mortars as well as try and get your hits on it, but there is a place you can sail where it won’t be able to hit you with them. Get up behind the Prince as fast as you can and stay there. Hit it with Chain-shots and rams and shoot some of your own mortars at it when it is slowed.
Once you are behind it, you can stay there for the duration of the fight and it won’t be able to hit you with any of its attacks until it gets down to about a quarter of its health. Once it is there and flaming, it will start to fire its rear cannons at you. It doesn’t do it often thankfully, and if you’ve gotten up behind it quick enough, you should have plenty of life to endure the rounds until you are able to sink it.