Back in the Animus, head for your ship in the Davenport harbor. Once you set sail for the Chesapeake, you'll receive some help from the French. You are going to need their help to get into the fort city in New York.
You'll almost immediately start a battle with eight ships appearing to starboard (right). One of the constraints is to destroy ships with a single broadside. To do this, don't shoot until you are right on top of one of the enemy ships. You want to make sure that you don't shoot unless it's sure to sink the enemy.
If you aren't interested in that method, you can use the swivel cannons to take out the smaller ships and save the large cannons for the bigger ships. After you've destroyed most of the early ships, more ships will appear on the horizon. These should similarly be easy.
When you've ruined 13 ships, you'll lose one of your own and be attacked by another fleet. As with last time, the small ships can easily be destroyed using the swivel cannons. The larger ships can be destroyed by using the large cannons and if you happen to damage one without destroying it, you may expose powder barrels in their holds. If you happen to see a white circle appear on the side of the ship, aim your swivel cannons at it to destroy the ship in a single shot. You have to do this to two ships to meet the constraint.
As with last time, when you've destroyed most of the five ships, three more will appear. These ships are easily the best candidate for the powder treatment because they are much larger and you'll likely damage them several times without actually sinking them. Just be sure to get close enough to them to deal the kind of damage necessary to reveal the powder kegs.
Finally, a Man-Of-War will appear, destroy your only other remaining ship and severely damage your own. Your only recourse is to ram the ship and board it. When you get on board, you will fight indefinitely until you kill the captain. In the first area, be sure to get all five counters before proceeding. After you've done that, you'll have to hop over some boxes to move further along the ship. When you do so, immediately turn left and ignore the enemies that are chasing/attacking you. There's no need to actually fight these enemies because they will constantly respawn and while you fight them, a firing line will continually shoot at you. Run past the firing line and turn left to chase after the captain. If you are successful in your chase, you can perform an air assassination while he's running to kill him instantly. Sometimes, he will reach his destination and turn around, preventing this. If this happens, disarm him and then you should have no trouble killing him.
