Upon accepting this contract, a red skull will appear on the map in the centre of Cumberland Bay which is a fair sailing distance to our northwest. A large red, circular restricted area will have made itself welcome in the area. Sail over to the island and dock/swim ashore.
We now need to enter the restricted area and use Eagle Vision to identify the target. If you have been here previously and used the viewpoint to synchronise the map, do not fast travel to the viewpoint if you want the bonus 500 Reales as there is a Gunner standing right beside it and he will spot you as soon as you appear before you can do anything.
As such, we’ll need to come in overland on foot. Either way you’ll find the target patrolling in and around some ledges just north of the viewpoint. Once identified, sneak up and dispatch him as you see fit. This will complete the contract.