After beginning the contract, we’ll first need to go and find the ship that we need to protect. If you look at your map, you’ll see that there is a large, green investigation zone to the northwest. Sail over here and pull out your spyglass to identify the target ship (I found it at co-ordinates: 146, 780).
As we approach, the ship will be at around half health and be taking fire from a pair of hostile gunboats. Sail in quick and use a broadside or chase cannons to take them out as quickly as possible. As the second ship sinks, another three will appear on the horizon to the north. Use mortars to target them as they approach and when they get in close, use the usual heavy shot/broadside combination to make short work of them.
Again, as we sink those hostile vessels another group will approach, this time from the east. It consists of a pair of brigs and two schooners. Again, use the mortars as they approach and try to eliminate the weaker schooners first before focusing on the larger brigs.
Once this final group of ships has been dealt with the contract will be complete.