What’s the Deepest A Snake Has Ever Been Found in the Ocean?

Written by Nixza Gonzalez
Updated: October 10, 2022
© Rich Carey/Shutterstock.com
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Think You Know Snakes?

Sea snakes are impressive. Usually, when we think of snakes, they are on the ground, in trees, or hiding in bushes. But some of the largest and deepest snakes are actually in the ocean! In fact, some snakes can swim deep down into the twilight zone. Ready to discover the deepest a snake has ever been found in the ocean? Keep reading!

What are Sea Snakes and How Deep Do They Swim?

Belcher's Sea Snake
Sea snakes are snakes which have adapted to live exclusively in the sea


Sea snakes, also known as coral reef snakes, are snakes that live in the sea. They are unique and can live underwater for most of their lives. Unlike land snakes, sea snakes cannot typically move on land. Some species of sea snakes can move on land but it is limited. They are often mistaken for eels because of their slippery and thin appearance, including their paddle-like tail. Almost all are venomous and will attack out of defense. The average sea snake is 4-5 feet long.

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But, how deep do these snakes swim? Sea snakes are active at all hours of the day. They are quick swimmers and divers. On average, most sea snakes live in depths as deep as 90 feet. Incredibly, these snakes can remain underwater for 8 hours. However, recently scientists have discovered sea snakes in the twilight zone. The deepest a sea snake has ever been found in the ocean was 803 feet. Footage of a sea snake swimming this deep underwater has surprised many scientists as the old record was 436 feet.

What is the Biggest Snake in the Ocean?

Yellow-bellied sea snake washed up on the beach
Yellow-bellied sea snakes can reach 4 feet in length, with females being slightly longer than males.

©John Fader/Shutterstock.com

There are 3,000 species of snakes in the world and at least 55 are sea snakes. The largest sea snake is Hydrophis spiralis (the yellow sea snake). Females on average grow up to 6 feet long while male yellow sea snakes grow up to 5.3 feet. The largest yellow sea snake ever found was 9.8 feet long. However, these snakes rarely grow more than 6.5 feet. Yellow sea snakes usually live in waters as deep as 164 feet.

These sea snakes are commonly found in the Indian Ocean, specifically on the coasts of Oman, United Arab Emirates, Pakistan, China, and Indonesia. They are super easy to spot since they have yellow and green scales. The yellow sea snake is also venomous and primarily hunts eels. They also eat small fish and fish eggs.

What is the Twilight Zone?

Sea Snake
Sea snakes have been found deep in the twilioght zone where little light exists

©Tomas Kotouc/Shutterstock.com

The twilight zone is not just a tv show, but a deep part of the ocean full of mystery. It is about 650 to 3,300 feet below the ocean’s surface. This is where the sun does not reach. This deepest part of the ocean is cold and dark, with sudden flashes of bioluminescence light from living organisms. According to recent studies, scientists believe wildlife is abundant in the deep twilight zone. A lot of small animals and organisms live in the twilight zone, including crustaceans and squid.

It is likely that there are many animals that we have yet to discover that live in these deep and freezing waters. The animals that live in the twilight zone look very different from the ones we see in the shallows. For example, the bristle mouth fish is a small fish that only lives in the twilight zone and has a large mouth full of spiny teeth.

Where Else Do Sea Snakes Live?

Sea snakes don’t live everywhere in the ocean. You can only find them in the Atlantic and the Indian Ocean. Although we have found some snakes in deep waters, most species live in shallow waters less than 100 feet deep. This is because they like warm and tropical waters and live near and in coral reefs since it is easier to find prey.

Fun Facts About Sea Snakes

  • The smallest sea snakes are about 20 inches long.
  • Most sea snakes have a flat head which they use to shoot through the water and swim quickly.
  • On average, these snakes weigh less than three pounds once fully grown!
  • Sea snake bites are rare. They typically stay away from humans.
  • Some species lay eggs while others give live birth to litters between 2 to 34.
  • Sharks hunt for sea snakes even though they are venomous.
  • Sea snakes cannot live in places with high salinity or cool temperatures
  • These snakes are old! They first evolved 6 to 8 million years ago.

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The Featured Image

Banded Sea Snake Krait
Banded Sea Krait
© Rich Carey/Shutterstock.com

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About the Author

I have been a professional content writer for 6 years now, with a large focus on nature, gardening, food, and animals. I graduated from college with an A.A, but I am still pursuing a Bachelors of Marketing degree. When I am not writing, you can find me in front of my TV with a blanket, snacks, and my fur babies.

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