After beginning the contract, we’ll first need to go and find the ships that we need to destroy. If you look at your map, you’ll see that there is a large, green investigation zone just to the southwest of our current location – in and around the island of Corozal. Sail down and into the inlet as if you were going to visit Corozal and you’ll find the blockade.
The blockade is made up of two frigates, a man o’ war and two gunboats. Stop outside of the inlet and rain mortars down on them. Turn away and sail slowly away from them, whilst looking backwards and firing mortars. When you get the message about sailing too far from the mission area, turn back and this time approach the blockade. You will notice that they have lost interest and are moving back to the inlet. As such, let’s go get them!
Continue to drop mortars on the ships as you approach. When you arrive, most of them should be destroyed or heavily damaged (depending on how accurate you were with mortars). So it’s a simple matter of mopping up any remaining enemies. Board/sink all of the ships to complete the contract.