There is an entire upgrade tree for your ship in Assassin’s Creed 4 Black Flag Resynced, but the absolute best upgrades are unavailable to you until you first acquire the associated ship plans for a selection of them. Finding these Ultimate Ship Plans is a task unto itself, and even the upgrades themselves require a great deal of resource hunting and Reales.
This Assassin’s Creed 4 Black Flag Resynced guide is about locating all twelve Ultimate Plans scattered around the map, as well as the available upgrades and required Reales and materials for each.
Unlocking And Accessing Ultimate Plans And Upgrades
You will have quite a bit of water to cover in the story before you can begin to acquire the most critical Ultimate Plans. These tend to be secreted deep underwater and thus are only accessible via the Diving Bell. That only unlocks during the mission titled “Diving For Medicine” which marks the start of Sequence 6, and will cost you a sum of 5,000 Reales, though you can also steal it for free from a pirate camp in Nassau’s vicinity; just chat with Adewale for clues.
The Ultimate Ship Plans that unlock through Treasure Maps usually involve storage and power upgrades, and are relatively easier to acquire, if a bit of a chore.
Hull Armor Ultimate Ship Plan
348,745 San Ignacio Wreck, Dry Tortuga
Requires the Diving Bell unlocked during the course of this very mission
Armored Hull I
- 1,000 Reales
Armored Hull II
- 4,000 Reales
- 100x Metal
- 200x Wood
Armored Hull III
- 15,000 Reales
- 200x Metal
- 500x Wood
Armored Hull IV
- Hull Armor Ultimate Plan
- 30,000 Reales
- 400x Metal
- 750x Wood
Ram Ultimate Ship Plan
149,272 La Concepción Wreck, Chinchorro
Requires the Diving Bell
Ram
- 500 Reales
- 75x Wood
Ram I
- 2,000 Reales
- 75x Wood
Ram II
- 5,000 Reales
- 150x Metal
- 250x Wood
Ram III
- Ram Ultimate Plan
Swivel Guns Ultimate Ship Plan
456,331 Devil’s Eye Caverns, Cruz
Requires the Diving Bell
Swivel Guns I
- 700 Reales
- 25x Metal
Swivel Guns II
- 5,000 Reales
- 200x Metal
Swivel Guns III
- Swivel Guns Ultimate Plan
- 15,000 Reales
- 400x Metal
Broadside Cannons Number Ultimate Ship Plan
440,145 The Blue Hole, Charlotte
Requires the Diving Bell
Broadside Cannons I
- 70x Metal
Broadside Cannons II
- 2,000 Reales
- 150x Metal
Broadside Cannons III
- 4,000 Reales
- 300x Metal
Broadside Cannons IV
- 8,000 Reales
- 350x Metal
Broadside Cannons V
- 12,000 Reales
- 500x Metal
Broadside Cannons VI
- Broadside Cannons Number Ultimate Plan
- 20,000 Reales
- 650x Metal
Round Shot Strength Ultimate Ship Plan
739,120 Navassa
Requires the Diving Bell
Round and Heated Shot I
- 900 Reales
Round and Heated Shot II
- 4,000 Reales
Round and Heated Shot III
- 12,000 Reales
Round and Heated Shot IV
- Round Shot Ultimate Plan
Mortars Ultimate Ship Plan
599,637 Antocha Wreck, Gibara
Requires the Diving Bell
Mortar
- 3000 Reales
Mortar I
- 3500 Reales
- 200x Metal
Mortar II
- 8000 Reales
- 300x Metal
Mortar III
- Mortars Ultimate Plan
Mortar Storage Ultimate Ship Plan
310,618 Buried Treasure Chest in Matanzas, Dry Tortuga
Requires the Treasure Map found at 848,352 Tortuga, Punta Guardico
Mortar Storage I
- 800 Reales
Mortar Storage II
- 2000 Reales
Mortar Storage III
- Mortar Storage Ultimate Plan
- 5000 Reales
Fire Barrel Strength Ultimate Ship Plan
455,461 Buried Treasure Chest in San Juan, Cruz
Requires the Treasure Map found at 188,218 Santanillas, Chinchorro
Barrel Launcher I
- 3000 Reales
Barrel Launcher II
- Fire Barrel Strength Ultimate Plan
Fire Barrel Storage Ultimate Ship Plan
40,372 Buried Treasure Chest in Tulum, Conttoyor
Requires the Treasure Map found at 864,237 Petite Caverne, Punta Guarico
Barrel Storage I
- 500 Reales
Barrel Storage II
- 1500 Reales
Barrel Storage III
- Fire Barrel Storage Ultimate Plan
- 4000 Reales
Heavy Shot Strength Ultimate Ship Plan
271,175 Buried Treasure Chest in Misteriosa, Serranilla
Requires the Treasure Map found at 28,159 Ambergris Key, Chinchorro
Heavy Shot
- 900 Reales
Heavy Shot I
- 6000 Reales
Heavy Shot II
- Heavy Shot Strength Ultimate Plan
Heavy Shot Storage Ultimate Ship Plan
863,237 Buried Treasure Chest in Petite Caverne, Punta Guarico
Requires the Treasure Map found at 299,310 Cayman Sound, Castillo de Jagua
Heavy Shot Storage I
- 500 Reales
Heavy Shot Storage II
- 1500 Reales
Heavy Shot Storage III
- Heavy Shot Storage Ultimate Plan
- 4000 Reales
Harpoon Strength Ultimate Ship Plan
544,692 Buried Treasure Chest in Andreas Island, Eleuthera
Requires the Treasure Map found at 845,515 Mariguana Island, Gibara
Harpoon I
- 1000 Reales
Harpoon II
- Harpoon Strength Ultimate Plan
- 4000 Reales
Those are the locations of all 12 of the Ultimate Ship Plans, and their upgrades in Assassin’s Creed 4 Black Flag Resynced.
