Upgrading the Jackdaw to its full potential requires finding every Ultimate Ship Plan scattered across the Caribbean. These rare blueprints are hidden inside treasure chests, Diving Bell locations, and other secret spots. This guide covers the location of every Ultimate Ship Plan, helping you unlock all Elite ship upgrades as quickly as possible.
How to Get All Ultimate Ship Upgrades
There are a total of twelve Ultimate Ship upgrades found behind either dives or treasure maps in AC Black Flag Resynced. Here’s how you can get all twelve of them easily:
Mortar Storage Upgrade
To get the Mortar Storage Ultimate Plan, you’ll need to get the treasure map from Tortuga at 851, 352 in northern Punta Guarico. After taking care of that, head to Jiquey Smuggler’s Cove in western Gibara. Make your way to the chest located at 534,510 to obtain the upgrade plan.
Harpoon Upgrade
To get its treasure map, you’ll need to go to Mariguana Island at 848,514 in central Gibara. After that, you’ll need to make your way to Eleuthera’s Andreas Island and open the treasure chest at 544,693 to get the upgrade.
Fire Barrel Storage Upgrade
The treasure map for Fire Barrel’s Storage can be found in Petite Caverne at 862,237 in the southern part of Punta Guarico. Once you’ve gotten the map, you’ll need to travel to Tulum in the southern part of Conttoyor and get the chest containing the upgrade from 40,372.
Elite Hull Upgrade
You’ll collect this plan during the Diving for Medicine main story mission at the San Ignacio Wreck near Dry Tortuga. After the underwater currents carry you into the shark-filled section, swim toward the Diving Bell but turn left instead. Inside a nearby wreck with a large hole in its side is a chest containing the Hull Armor blueprint.
Heavy Shot Storage Upgrade
The Heavy Shot Storage treasure map can be easily retrieved from the southern part of Castillo de Jagua in Cayman Sound’s at 298,311. After getting the map, travel to Petite Caverne Smuggler’s Cove in southern Punta Guarico and dig up the treasure at 863,235 to obtain the upgrade.
Fire Barrel Strength Upgrade
The Fire Barrel Strength’s treasure map can be retrieved from Santanillas at 191,218 in Chinchorro. After getting it, you’ll need to head to the San Juan Smuggler’s Cove in Cruz at 455,462 to get the upgrade.
Heavy Shot Strength Upgrade
To get the Heavy Shot Strength, you’ll need to get its treasure map at southern Chinchorro from the Ambergris Key at 28,160. Once you have the map, travel to Misteriosa in central Serranilla at 271,178 to find the buried treasure chest and get the upgrade.
Mortar Strength Upgrade
For getting the Mortar Strength treasure map in the game, you will need to go to the Antocha Wreck diving site at 601,633 which is near the Gibara. Once there, you’ll find a broken shipwreck close to the southern edge of the underwater area. You’ll find a chest there with the blueprint inside it.
Roundshot Strength Upgrade
For the Roundshot Strength, you’ll need to go to the diving location at 738,120 near Navassa. You’ll need to swim through the cave network until you reach the northern part of the map. After that, you’ll need to pass through a narrow tunnel and hide inside the small cave on the right while waiting. The blueprint can be found inside a chest at the end of the passage.
Swivel Guns Upgrade
Head to Devil’s Eye Cavern at 453,331 in Cruz. Swim north through the underwater tunnels until you reach a large cave with an open ceiling where Edward can stand. From there, take the tunnel on the left to find a treasure chest containing the upgrade plan.
Broadside Cannons Number Upgrade
At The Blue Hole diving location (440,145) near Charlotte, explore the northernmost part of the dive. Stay near the seabed and search inside the remains of a damaged ship to locate the blueprint chest.
Ram Upgrade
The Ram blueprint is located in the La Concepción Wreck at 150,271 in Chinchorro. After entering the dive, swim directly north from the Diving Bell to a shattered section of the wreck. The treasure chest is hidden inside this broken area.
