Leatherbacks are the largest species of sea turtle; the average carapace (shell) length of females nesting in the western Atlantic is about five feet. Leatherbacks are tropical nesters for the most part, but some females do nest on beaches in Florida. When these turtles aren't reproducing, they spend most of their time leading a pelagic existence. They spend their time in temperate and even polar waters, feeding on aggregations of jellyfish (their preferred food).

Like other sea turtle neonates, once leatherback hatchlings emerge from the nest, they too enter the ocean and begin a pelagic existence. However, their developmental habitat has not yet been discovered and therefore little is known about these turtles between their hatchling and adult life stages.