5. Give Your Cannons a Rest and Ram Your Opponent
Sometimes brute force is the answer:

Ramming: If your ship has a strong hull, consider ramming your opponent. Ramming can cause significant damage and is often less risky than extended cannon exchanges.
6. Don't Forget to Skull and Bones Items Brace Yourself
Bracing is your defensive move:

Damage Reduction: Press the right shoulder button to “brace” your ship, reducing incoming damage. While bracing consumes stamina, it can be used frequently, so don’t hesitate to Skull and bones items for sale cheap use it when under fire.