How to get all 12 Ultimate Ship Plans in Black Flag Resynced

The Elite Ship Upgrades from the original game have been renamed in Assassin's Creed Black Flag Resynced. Now called Ultimate Ship Plans, these schematics still serve the same purpose: fully upgrading the Jackdaw. So you'll want to find each and every one of the locations if you're hoping to take on the legendary ships.

All Black Flag Resynced Ultimate Ship Plan locations

(Image credit: Ubisoft)

There are 12 Ultimate Ship Plans for you to find, locked behind either dives or treasure maps. You'll need to complete the first Sequence 6 main mission, Diving for Medicine, before you can start hunting for the plan locations in earnest, since this unlocks the diving bell, and most of the plans are located underwater.

Once you've found the plan, you then need to head to any shipmaster to purchase the upgrades for your ship—they're not free, unfortunately, costing both Reales and materials.

Here's where to find all 12 Ultimate Ship Plans in the remake:

Ultimate Ship Plan	Location
Round Shot Strength	Kabah Ruins (738,120) diving bell, Navassa: In the cave at the north point of the dive map, through the tunnels. You'll have to wait for the current passing through to get by, sheltering in the cave off to the right, before swimming on. There are air pockets in the ceiling of any room with oxygen streams.
Heavy Shot Strength	Misteriosa treasure map: Collect the map from Ambergris Key, southern Chinchorro (28,160), and the chest from Misteriosa, central Serranilla (271,178).
Fire Barrel Strength	San Juan treasure map: Collect the map from Santanillas, Chinchorro (191,218), and the chest from San Juan smuggler's cove in Cruz (455,462).
Mortar Strength	Antocha Wreck (601,633) diving bell, Gibara: In a chest in the open wreck at the southernmost point of the area on the map.
Swivel Guns Strength	Devil's Eye Cavern (453,331) diving bell, Cruz: Head north through the tunnels and follow them around until you reach the open-air cave you can walk around. On the left side, down a tunnel, you'll find the chest.
Broadside Cannons Number	The Blue Hole (440,145) diving bell, Charlotte: At the far north end of the dive, at ground level, in a bit of a broken-open wreck.
Ram	La Concepción Wreck (150,271) diving bell, Chinchorro: In the broken bit of ship directly north of the diving bell, very close to where you first enter.
Hull Armor	San Ignacio Wreck dive, Dry Tortuga, during the Diving for Medicine main mission: After you get propelled through the caves by currents and enter the section with the sharks, head towards the diving bell, but then turn left to find a ship with a hole in the side containing a big chest.
Heavy Shot Storage	Petite Caverne treasure map: Collect the map from Cayman Sound, southern Castillo de Jagua (298,311), and the chest from Petite Caverne smuggler's cove in southern Punta Guarico (863,235).
Fire Barrel Storage	Tulum treasure map: Collect the map from Petite Caverne in southern Punta Guarico (862,237), and the chest from Tulum, southern Conttoyor (40,372).
Mortar Storage	Matanzas treasure map: Collect the map from Tortuga in northern Punta Guardico (851,352), and the chest inside Jiquey smuggler's cove, western Gibara (534,510).
Harpoon Strength	Andreas Island treasure map: Collect the map from Mariguana Island in central Gibara (848,514), and the chest from Andreas Island, Eleuthera (544,693).

Black Flag Resynced new content: How to access
Black Flag Resynced treasure maps: Solve each one
Black Flag Resynced outfits: Dress to kill
Black Flag Resynced Mayan Stones: All locations
Black Flag Resynced Data Fragments: Animus projects

source https://www.pcgamer.com/games/assassins-creed/black-flag-resynced-ultimate-ship-plan-locations/