Assassin’s Creed 4 Black Flag Resynced Hull Armor Ultimate Plan Location

Hull Armor Ultimate Plan in Assassin’s Creed IV Black Flag Resynced is needed to buy the final Hull Armor ship upgrade at the harbourmaster.

Hull Armor Ultimate Upgrade Plan Location

Hull Armor Ultimate Plan is looted from an underwater chest in San Ignacio Shipwreck (348, 744).

For all other Plans refer to All Ultimate Upgrade Plan Locations and for everything else also check the Collectible Guide.