A member of a group of species of turtles adapted for life in the sea. Sea turtles have flipper-like legs and come to shore only to lay their eggs.

Sea turtles (Chelonioidea) are turtles found in all the world's oceans with the exception of the Arctic Ocean, and some species travel between oceans. The Flatback turtle is found solely on the northern coast of Australia. The Leatherback Sea Turtle is the largest, measuring six or seven feet (2 m) in length at maturity, and three to five feet (1 to 1.5 m) in width, weighing up to 1300 pounds (600 kg).