All reptiles have tails with many different uses for them - Aiken Standard (subscription)

At least 32 species of sea snake have been recorded in northern Australian waters. Some species are also found in the southern waters off Victoria, Tasmania and South Australia. All sea snakes discovered so far are venomous. Sea snakes are readily identified by their flattened tails and valvular nostrils. They are of course excellent swimmers and divers and feed on fish and eels. The young are born alive at sea, except for those of the banded sea krait (Laticauda colubrina), which comes ashore to lay its eggs. Sea snakes shed their skins much more frequently than land snakes; as often as every two weeks.