Assassin’s Creed 4 Black Flag Resynced Broadside Cannons Number Ultimate Plan Location

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

Broadside Cannons Number Ultimate Upgrade Plan Location

Broadside Cannons Number Ultimate Plan is looted from an underwater chest in The Blue Hole Shipwreck (440, 145).

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