The elephant seal is the largest species of seal in the world with the average male elephant seal growing to around 5 m long. The female elephant seals are generally quite a bit smaller than the male elephant seals, and the female elephant seals therefore grow to around 3m.
Elephant seals are able to hold their breath underwater for over 2 hours, which is the longest of any water-based mammal. The elephant seals dive to depths of around 500 meters to hunt for food but some elephant seals have been observed diving to more than 1,500 meters underwater. The male elephant seals are able to stay at such depths for up to an hour, but the female elephant seals tend to resurface after approximately 20 minutes.
Elephant seals have a thick skin and fur to keep them warm in the freezing cold waters, but it is the thick layer of blubber that the elephant seal has under its skin that does the best job at insulating the elephant seal. The skin of the elephant seal molts every year and the elephant seals have to find land in order for the old skin of the elephant seal to molt and the new of the elephant seal to regrow. The molting process of the elephant seal does not occur during mating season, so the male elephant seals are able to stop fighting as there are no child-bearing females to protect.