Assassin's Creed 3 – Captain Kidd's Treasure – The Ghost Ship

This Peg Leg Mission is available after collecting 14 trinkets.
Optional Objectives:
Do not fall into the water
Reach the Octavius within 1 minute

Things start quickly here. Head forward through the ice canyon. If you are after the optional objectives, there is a checkpoint just at the start of this section so reset if you fail the timer or fall into the water. Have Connor start down the slope in front of him immediately. Once he reaches the bottom turn to the left and move quickly toward the ship. Head the slope and to the edge of the outcropping. Start ot the right from there and onto the next large chuck of ice. Reach the pinnacle of that and Connor will jump over to the next one. Keep your balance on the narrow beam of ice and head to the V-branch in front of you. After that, head either left or right but keep moving forward. After that, jump to the next solid block of ice. Just move forward from there to complete the optional time objective. It will be cleared once Connor is close to the frozen wooden planks he must duck under.

Before going forward, head over to the right. Behind the last tent you will find a chest with £1250 inside it. Now head back to the left and climb up the nearby ice block. On top of it head to the left and jump to the next iceburg. Head to the right and climb around the ice until Connor starts upwards. Once he does, just head along the path in front of you to get to the Octavius quickly.

Once on the Octavius, head for the bow and then go over the port (left) side. There you will find a chest with £2500 inside it. Climb back onto the ship after that and head for its stern. You will find a second chest with £1000 inside it. Now head north and drop through the opening in the deck. Drop down and go South to find the Captain's quarters. Connor goes over what he knows. Head to the marker to claim your third map piece. There is one left now.

Head forward to trigger another cutscene. The Octavius is now falling apart. Start by running straight forward and ducking underneath the gap in front of Connor. From there swing around the corner and then run up the boxes to the right. Another cutscene will begin.

After that, start running up the Octavius to the right. Turn left after that and head over to the ladder. Connor will fall again. You now have 50 seconds to get out of the ship before it sinks. Run for the far wall and climb up it. Once at the top and the camera shifts, finish the climb up and then jump out to grab onto the hand holds above so Connor can swing across the rising water. Go from there to the next wall. Climb up it and back eject when prompted. Just climb upwards from there and head over to the right. You will find yourself somewhat stuck at a point, just jump for the door you came through and you will find your way back up. Just keep climbing up and to the right from there to make to the top and finish this mission out.