Optional Missions:
- Sabotage the alarm bell
- Kill 3 guards while hanging from a ledge
Locate the woman on Nassau beach to begin the mission. Covertly tail the pirates and British reps as they move around the city. You can follow them in the open, just stay away from their restricted space. If you decide to follow them on the rooftop, make sure you take out any gunners as well.
Once they reached the fort, wwait outside while hiding in the bushes as they converse. Your main objective will then tell you to infiltrate the fort. There's a wooden platform in the southeastern corner of the fort where you can climb and scale the damaged portion of the wall. There's also a couple of gunners in the two buildings beside the fort which you can kill by pulling them over the ledge while you're hanging. (Counted towards the optional objective). Make sure you're unarmed and they must die upon hitting the ground for the kills to count. As soon as you enter the fort, your main objective will be updated.
For your second optional objective, you'll find the bell in the northeast part of the fort. For your convenience, theres are some ample cover that will help you get near it. It will help taking out the guards on the walls to make your job easier. After sabotaging the alarm bell, head towards the marked building and steal Chamberlain's plans on top of a barrel near the door. The mission will be complete afterward.