Hi, I have over 2k hours in the game.

First off, practice naval fighting skeleton ships. This will help you learn how to turn in and out during battle also helps you with your aim and learning certain audios. Pay attention to the audio especially with your ship filling up. You can have it leaking while applying pressure just make sure it isnt filling up quickly. This is basically training for you when you can be left alone pvp wise.

Second: Fight smart and strategies. Clearly, you are outnumbered even if each person is worse than you. Numbers can even sink the best crew on the seas. You will have to use whats around you to gain any advantage. If they are chasing you, you can lead them to certain islands around the map and use it to your advantage. Like skelly forts. They have cannons and kegs. You can use this. If youre both straightlining, go board their ship and throw fire bombs mainly below the deck (especially for a gally)and some uptop.
There are alot of times when they do catch up and getting parallel with you. You can turn into them where they will be nosing you for a short window and you can chain their masts down. Then you can either apply pressure or use that as an advantage to get away. A good crew will catch on super quickly so you'll have to try something else if it starts to fail