After killing the assassin, Edward must find a way to Havana in AC4 Black Flag

"Find a way to Havana" is a mission objective in Sequence 1/Memory 01, Edward Kenway

Walkthrough

After killing Duncan Walpole and assuming his identity, Edward must find a way to reach Havana and collect a reward

To complete this objective, just head towards the next Viewpoint to the east, which is just a big branch of a tree extending over a body of water below. Once you get to the edge of the branch, synchronize, and perform a Leap of Faith to the water below, the objective will complete.

Next Objective

Free the merchant