Assassin's Creed 3 – Naval Mission: The Chase
Optional Objective:
Limit the Ship's Damage to 50%
This is a tricky thing to pull off as there are a number of ships that will come and attack the merchant ship that is making its way to Martha's Vineyard. You must keep up with the Merchant Vessel and make use of the long range abilities of the Swivel Guns. Pulling that off takes some careful timing as the Red Targeting time is very limited. If you encounter a group of gunboats, use a broadside to quickly destroy them then correct your course. A careful use of half and full sail will get you through this part with the objective complete.
Optional Objective:
Limit the Ship's Damage to 50%
Use a mine to Eliminate a gunboat
After Connor has to stop because he is blocked by 2 sets of mines you receive the new objective. The new objective is just as tricky. After you destroy the initial line, look to the left. You will notice a low lying rock with a gunboat just beyond it. First though look right and shoot down the gunboat just beyond where the initial line of mines were. Wait until the Aquila has a clear view of the mines on the left and then fire at them with the swivel gun to quickly take out the gunship behind that rock.
After that, look forward and either go full stop or quickly aim and fire on the next line of mines that are in front of you. Whichever side you clear, steer over to it and head through. Just before you get to the start of the area you cleared. Look forward and fire on the next set of gunboats in front of you. As you set into the path, look forward and you will notice another line of mines in the distance you need to destroy. Just fire on them when you get a clear shot.
Shortly after, there is a lot to do. Look right and you have a gunboat. In front of the Aquila you have another 2 channels trapped with mines. Use a broadside to take down the ship and immediately after turn your attention toward the mines and fire the swivel guns on them.
Once on the other side of this line of mines you will see the merchant vessel break away and turn to safety. To the right there are a number of gunboats that need to be dealt with. Chase the gunboats and they will lead you to the fort and the final part of the mission.
Optional Objective:
Limit damage from the Fort's mortars to 50%
Now in addition to any surviving gunboats you have the fort to contend with. Use the swivel cannons on the gunboats and start a run parallel to the shore with a broadside ready to fire. Come at it with full sails. Just before the fort fires on the Aquila cut to half sail and turn hard away from it. This will still allow the broadside to connect and destroy the mortar while keeping the Aquila from most of the damage.
Mix up how to move away. When trying to position the Aquila for another broadside, turn toward the fort itself when it opens fire with the mortars. Only when you are attacking with a broadside should you break away from it. Even then, mix it up as the situation demands. It is hard to do but careful use of these principles will carry the day.