I can’t be sure of the absolute record for all crocodilians, but the American Alligator can remain submerged in very cold water for at least 8 hours. The temperature of the water is important because the cold-blooded alligator’s metabolism will operate more quickly in warmer water which makes the cells use up oxygen more quickly. Because the American Alligator is found in the coldest climate of any crocodilian, I assume that it is the record holder for longest dives.
