Plunder Kampong Subur
Set sail and head north to the other side of the island, to Kampong Subur. There will be an optional step to destroy the towers with the termites as well. When you approach the dock, you can choose to interact or plunder. You will want to plunder and release your crew onto the dock to Skull and Bones Items kill all the enemies.
Across from the dock, you will see a stone tower structure that you must destroy with the Termites. There will be a couple of others within this vicinity as well that you must destroy. Don't forget to use the Termites. Keep moving as you will be under fire as you're attacking.
Keep an eye on the AoE indicated by a large red circle on the ground. Plunder again, sending your crew on shore, then attack the main tower near the docks. Don't forget to Skull and bones items for sale cheap keep an eye on your health and heal as needed. This should take care of the optional task and allow you to focus solely on the plundering.
You'll see loot floating in the water. Make sure your inventory isn't full, so you can take it. Enemies will soon swarm the waters, and you must take them out with the termites. After you take out every ship within the perimeter, this will complete the mission.
The Wall