Complete the indicated task to unlock the corresponding cheat under the "Cheats" option at the "Abstergo Challenges" menu. Enabling a cheat will prevent the game from being saved.

Cheat	How to unlock
Armed to the Teeth	Complete 90 Abstergo Challenges.
Arrr Matey!	Complete 20 Abstergo Challenges.
Celestial Navigation	Complete 10 Abstergo Challenges.
Dead Men Tell No Tales	Complete 70 Abstergo Challenges.
Deceased Crew	Complete all 100 Abstergo Challenges.
Loaded to the Gunwhale	Complete 50 Abstergo Challenges.
No Quarter	Complete 30 Abstergo Challenges.
Poseidon's Will	Complete 60 Abstergo Challenges.
Scourge of the Seven Seas	Complete 40 Abstergo Challenges.
Shiver Me Timbers	Complete 80 Abstergo Challenges.