Dangers HereSea snakes: highly venomous, rarely a threat
Sea snakes carry venom more potent than most land snakes, and they are also among the least aggressive animals a swimmer will meet. They are curious rather than hostile, their fangs are short, and the overwhelming majority of bites happen to fishermen handling nets rather than to swimmers or divers.
- 0High risk
- 5Medium
- 5Low
- 10Zones tracked
Why bites are dangerous when they happen
A sea snake bite is often painless and leaves marks so small they are missed. Symptoms appear over the following hours: muscle pain and stiffness, drooping eyelids, difficulty swallowing, and in severe cases paralysis of the breathing muscles. Because the bite itself is unremarkable, the delay in seeking help is what makes them dangerous.
Behaviour in the water
A sea snake approaching a diver is usually investigating, not attacking — they are short-sighted and inquisitive. Staying still and allowing it to pass is the correct response. They must surface to breathe, so encounters concentrate in shallow reef and lagoon water.
How to avoid it
- Never handle a sea snake, including one that appears dead or stranded on a beach.
- Do not touch or grab at one that approaches you underwater — stay still and let it move on.
- Be careful around fishing nets and catch; this is where nearly all bites occur.
- Wear full-length exposure protection when diving in reef and lagoon systems where they are common.
If it happens
- Apply a pressure immobilisation bandage to the whole limb and splint it, keeping the person as still as possible.
- Get to hospital urgently even if there is no pain and no obvious wound.
- Note the time of the bite and, if safe, the snake's appearance — do not attempt to catch it.
- Do not cut, suck or apply a tourniquet.
General guidance only — not a substitute for medical advice or local emergency services.
Where we track it
10 zones in the Dangers Here hazard database, by danger level.
Medium
- Great Barrier Reef & Coral Sea
- Indonesia (Coral Triangle)
- Northern Australia (NT Coast)
- Papua New Guinea
- Philippines (Visayan Reefs)
Low
- Fiji
- New Caledonia Lagoons
- Persian Gulf
- Sri Lanka & South India Coast
- Vietnam & Gulf of Thailand
Questions
Where are sea snakes a risk?
We track 10 zones for this hazard. 5 are rated medium and 5 low.
How do you avoid sea snakes?
Never handle a sea snake, including one that appears dead or stranded on a beach. Do not touch or grab at one that approaches you underwater — stay still and let it move on. Be careful around fishing nets and catch; this is where nearly all bites occur.
What is the first aid for sea snakes?
Apply a pressure immobilisation bandage to the whole limb and splint it, keeping the person as still as possible. Get to hospital urgently even if there is no pain and no obvious wound. Note the time of the bite and, if safe, the snake's appearance — do not attempt to catch it.
Why bites are dangerous when they happen
A sea snake bite is often painless and leaves marks so small they are missed. Symptoms appear over the following hours: muscle pain and stiffness, drooping eyelids, difficulty swallowing, and in severe cases paralysis of the breathing muscles. Because the bite itself is unremarkable, the delay in seeking help is what makes them dangerous.
Get the alerts on your phone
Dangers Here warns you when you enter a hazard zone — even offline, even with the app closed. No account, no tracking, free.
Other hazards
- Africanised bees
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