User blog comment:Master Sima Yi/Assassinews 25-03-'13 — Assassin's Creed IV: Black Flag gameplay trailer/@comment-4504019-20130327101757/@comment-25395574-20130327232355

The time expended underwater can be extended with practice and the ablity to remain calm, there are people that last more than 7 minutes underwater, though, not even Edward can remain that calm in battle against a Shark.