Assassin's Creed 4: Black Flag Walkthrough Part 17 – Sequence 3: “A Single Madman”

Optional Objectives:
Stay out of combat
Air assassinate Du Casse

When you make it to the marker, drop anchor and head ashore. Just start the mission when you enter the area. Edward will appear on shore. Head for the overhang on the right and start your climb up there. Head on up the planks then get to the landing above you. Turn to the left and swing over to the far side. Turn to the right and run up the wall to continue the climb. Head on up the planking then start shimmying over to the left. Continue on upwards and then over to the right. When you reach the first plank jutting out of the wall, climb on up the wall. There you will find the chest (it helps to mark it via the map). From there just drop back to the plank then head on up the broken bridge on the far end of the course to get up to more solid land.

Once at the top, head along the path until it starts bending to the left. As soon as you can, duck into a Stalking Zone. There is one just as the bend is finishing. Wait inside the Stalking Zone. There is a single Soldier patrolling the area. Lure him close and take him down. Continue on forward. While there are a lot of paths in front of you, Edward needs to focus on his objective to avoid getting too far into the jungle. The proper path forward is going to have guards on it.

They are talking about having hit something. Drop down and move into the Stalking Zone that is nearby them. Wait the guard to start his patrol before doing anything .He will be going around a tree in a circle. While he is heading behind it have Edward whistle at the other guard to lure  him in and assassinate him. Move along the Stalking Zone to the far end, near the patrol route. When he is close, lure him in and take him out.

Head along the path toward the next 2 guards. One of them is patrolling around some ruin's wall. Wait for him to be on the side with the rocks and take him out. Move forward and duck through to the next Stalking Zone. Ahead is a stationary guard. Move into the Stalking Zone behind him and then lure him in for an easy kill. Continue on forward, ducking under the tree.

Past the tree, use the corner to spot and mark the final Soldier. He is patrolling the area. While he is turned away, you can rush in and assassinate him or just move into the Stalking Zone by him and assassinate him from there. After that it is straight forward and no further hazards will be presented for a section. Make the jump onto the tower of rock with the collapsed bridge. Take a moment to grab the chest on there then turn to the East and head across the beam to the marker.