It is often said that a sea snake can only bite humans in the thin skin between the fingers or in the ears as its mouth is too small to grab anything else. This story took away the fear of sea snakes from many new scuba divers (and probably some experienced ones too). But is it true or just a myth?

Most sea snakes found in warm coastal waters are highly venomous. The most common snake observed by scuba divers is black and white with the common name of the banded sea snake. It can often be seen swimming over and between the reefs sticking its head in every hole looking for prey. Sea snakes need to breath and can therefore also be observed while free swimming up to the surface for air.

olive green sea snake

Scuba divers often hear during their open water courses that the snakes are not dangerous for humans as their mouth is too small to bite us. I was told this as well. And I heard this over and over again. I did not question it till I saw a documentary of pearl farmers who are at risk of getting bitten by exactly this banded sea snake that I was told cannot bite.

banded sea snake

So workers at pearl farms as well as fishermen do get bitten. The snakes get entangled in fishing nets or hide in the crates where the pearls grow. They then feel threatened when taken out of the sea and bite in self-defense. But – they can’t bite humans, correct?

No, not correct. Sea snakes can indeed bite humans. To swallow their prey, which can be more than twice the size of its neck, the snake has to be able to open its mouth widely. It can obviously do so as well to bite in defense.

sea snake

However, under normal circumstances a sea snake would never attack a scuba diver, snorkeler or swimmer. Also the fangs of most species are not long enough to reach through wetsuits. As always, treat sea life with respect. Don’t put your hand inside holes in the reef, don’t molest the animals, stay away from mating snakes and don’t block the way of a snake on its way to the surface to breath and you will be fine.

Just recently I met one of the guys who made up this legend many years ago on an island in Thailand. Fascinating how this tale made it around the world and almost every diver has heard it, many believing it.

sea snake

Sorry for debunking this myth but probably it’s better to know about the dangers and to handle marine life with respect than to erroneously feel safe. Let me repeat, sea snakes are not aggressive; they never just attack without a reason. It would only do so if it feels in danger. If one comes close just let it swim past you. I have done this many times, it’s fine.

When photographing a sea snake and you want to get a nice front shot, swim ahead of the snake, wait for it at a distance and let the snake approach. If it approaches on its own it will not feel threatened and you get your perfect shot. Or alternatively you breath in (and go up) because you now know that they can actually bite you!


Have you heard the story about the small mouth of the sea snakes before? Who told it to you?