Sea Snakes

Sea snakes are true reptiles — air-breathing, scaled, descended from land-snake ancestors that returned to the ocean. The banded sea krait (Laticauda colubrina) is the most photogenic — black-and-white-ringed body, paddle-shaped tail, daytime reef hunter that returns to land to digest, mate and lay eggs.

They're highly venomous (more potent than cobras in some species) but extraordinarily non-aggressive — almost no recorded bites on divers despite huge encounter rates. The mouth is too small to easily bite an adult human, and they show no defensive interest in being approached.

Sipadan, Komodo, Philippines (Cebu, Coron), Andaman, Phuket. They hunt in reef cracks for moray eels and small fish — follow respectfully and you can watch the hunt and the surface-breath cycle (every 15–30 min) on the same dive.