The human body is possible of a lot more than most people think. It is not designed to survive 60 days of non-stop swimming, but it will withstand battling big waves and cold ocean water for 6-8 hours a day for weeks in a row, as several long-distance swimmers have proven. The longest swims are classified in several categories – with or without a shark cage, using a wetsuit or flippers or not, non-stop or taking breaks every few hours. All of them test people to their mental and physical limits with sharks, poisonous jellyfish, dolphins and storms along the way.