To be able to view and use single-player content in-game, you need to reach Sequence 3, Memory 4
, when you will gain access to the Jackdaw.
All of the additional equippable
content can be accessed inside of the captain's cabin on-board the ship.
Pistols, swords and outfits
Approach the mannequin and press the change equipment button. From here, you will be able to equip any redeemed weapons and outfits.
Ship sails, figureheads and wheels
Approach the Jackdaw model located on the desk and press the outfit ship button. From here, you will be able to view, buy and sell the redeemed content.
Additional islands can be found in the following locations on the world map:
Black Island: East part of Gibara
Mystery Island: East part of Navassa
Sacrifice Island: East part of Castillo de Jagua