There is a total of 12 elite design plans that you can find in Assassin’s Creed 4 Black Flag. These design plans add different dimensions to your ship by strengthening your cannons, increasing mortar storage, or increasing the potency of your harpoons.
Finding all elite design plans will net you a ship that can survive the onslaught of pirate hunters and fight the legendary ships you might encounter during your adventures. If you want to upgrade your ship to the fullest, you must find all the buried treasure chests and loot all the chests in underwater shipwrecks.
Elite Ram
Location: La Concepcion Wreck, 181,296
The Elite Ram upgrade design plan is in the La Concepcion underwater shipwreck in Black Flag at 181,296; go down the small staircase from the mast platform to retrieve it.
Elite Swivel Guns
Location: Devil’s Eye Caverns, 488,353
The Elite Swivel Guns upgrade design plans are found in the Devil’s Eye Caverns underwater shipwreck at 488,353; take the tunnel nearby and swim with the water current to a water pocket. After replenishing your oxygen supply, exit the water near the slope and head up to retrieve the plan from the chest.
Elite Mortar Storage
Location: Mantanzas, 333,650
You will find The Elite Mortar Storage upgrade design plan in Matanzas in Black Flag at 333,650; in a buried treasure chest near the ruins. You will find the treasure map for this design upgrade in Tortuga.
Elite Hull Armor
Location: San Ignacio, 379,770
The Elite Hull Armor upgrade design plan is in the San Ignacio underwater shipwreck at 379,770. After you’ve reached the sea floor, replenish your oxygen, and then head straight to the wreckage. The chest will be in plain sight.
Elite Round Shot Strength
Location: Kabah Ruins, 769,145
You will find the Elite Round Shot strength upgrade design plan in the Kabah Ruins underwater shipwreck at 769,145. Look inside the lower level of the ruins on the opposite side of the shipwreck.
Elite Broadside Cannons
Location: The Blue Hole, 471,170
You will find the Elite Broadside Cannons upgrade design plan in the Blue Hole underwater shipwreck at 471,170. The chest will be found just beyond the shipwreck before a narrow rock crevasse. Make sure to replenish your oxygen constantly.
Elite Mortars
Location: Antocha, 630,660
You will find the Elite Mortars upgrade design plan in the Antocha underwater shipwreck in Black Flag at 630,660; from the corridor northeast of the fore section of the wreck, go through the small opening to find it. It’s a bit tricky since there is a shark nearby, but you can avoid her altogether using two patches of the seaweed.
Elite Heavy Shot Strength
Location: Misteriosa Island, 307,195
You will find the Elite Heavy Shot Strength upgrade design plan in Misteriosa Island in Black Flag at 307,195; in a buried treasure by the giant structure. You will get the treasure map for this buried treasure in Ambergris Key.
Elite Fire Barrel Strength
Location: San Juan, 479,487
The Elite Fire Barrel strength upgrade design plan in San Juan is located at 479,487. In the Smuggler’s Den, break the wooden planks and clear the smugglers to locate the buried treasure chest. You will need a Santanillas treasure map to dig this buried treasure.
Elite Heavy Shot Storage
Location: Petite Cavern, 901,263
You will find the Elite Heavy Shot Storage upgrade design plan in Petite Cavern at 901,263. The buried treasure chest is in the restricted section of Petite Cavern near the fire next to small rocks. You will find the treasure map for this buried treasure in Cayman Sound.
Elite Fire Barrel Storage
Location: Isla Providencia, 502,44
You will find the Elite Fire Barrel Storage upgrade design plan in Isla Providencia at 502,44. The buried treasure chest can be found along the southern coastline near the wrecked ship. You will find the treasure map by sending Kenway’s fleet to Eastern Canada and completing the ‘Scarlatina’ mission.
Elite Harpoon Strength
Location: Andreas Island, 579,720
You will find the Elite Harpoon Strength upgrade design plan in Andreas Island at 579,720. The buried treasure chest can be found near a couple of palm trees by the coast. You will get the treasure map for this buried treasure at Mariguana Island.
