Discover the Largest Banded Watersnake Ever Recorded

Written by Cindy Rasmussen
Updated: August 29, 2023
© Capps
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Key Points:

  • Banded water snakes are excellent swimmers capable of remaining immersed for two hours.
  • They are also skilled climbers and love to slither among tree branches.
  • Although they closely resemble cottonmouths, they are nonvenomous and do not have mouths that open to reveal a white interior.

The Banded watersnake is a medium-sized snake that is semi-aquatic spending much of its time in lakes, rivers, swamps, and marshes.

They are nonvenomous and live in the United States along the coastal plains of North Carolina down to Florida, as well as along the coast of Texas. There are three sub-species based on location including the southern watersnake, broad-banded watersnake, and Florida watersnake.

Their coloration varies but many have a light brown base color with dark brown bands going around their bodies. With an average size of 2-5 feet, what is the largest banded watersnake ever recorded? Let’s find out!

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All about the Banded Watersnake

banded water snake in the water
Most banded watersnakes are 2-5 feet long.

© Capps

The banded watersnake is an excellent swimmer and glides across the top of the water. It can also hold its breath for a long time and dive for food (or to avoid prey) for up to two hours underwater! If you are out hiking through the mangroves and you are scanning the trail or waterways for snakes, you might want to also look up.

Banded watersnakes are good at climbing trees and will often hang on the branches over the water to the sun themselves. If approached, they will typically swim away but if they are picked up (or tried to pick up) they will flatten their head to make themselves look big and then strike repeatedly. They are not poisonous but the bites will be painful, so it is best to leave them alone!

What is the Largest Banded Watersnake Ever Recorded?

Infographic for the Largest Banded Watersnake Ever Recorded.
Since the banded watersnake looks like a water moccasin, it is best to keep your distance, just in case.

According to the Florida Museum, the largest banded watersnake ever recorded was 62.5 inches long! This one was the subspecies of banded watersnake, the Florida watersnake. When they get to be older they gradually start turning darker over the years. It is often confused with the Florida cottonmouth (water moccasin) which looks a lot like the banded watersnake.

The problem with cottonmouths is that they are extremely venomous and should be avoided at all costs. Many banded watersnakes are mistakenly killed thinking they are the cottonmouth. One of the main differences is that the cottonmouths have elliptical pupils whereas the watersnakes have round ones. If you don’t want to get that close, assume the larger, thicker-bodied snakes are cottonmouths, or better yet avoid them all!

Cottonmouth swimming in water. The snake has a long, thick, muscular body measuring up to 6 feet in size.
Cottonmouth snakes look like banded water snakes, but they are a little thicker and have white mouths.

©Seth LaGrange/

Are Banded Watersnakes the Largest Watersnakes in the US?

No. The Diamondback watersnake is the largest watersnake in the United States. Diamondback watersnakes are larger than cottonmouths but are nonvenomous. They grow to be 3-5 feet or more but can weigh 5-15 pounds, so they are heavier snakes.

They have a light brown base color with dark brown diamond shapes along their backs. Diamondback watersnakes live along the eastern coast of the US. The longest diamondback watersnake was recorded to be 98.4 inches (8.2 ft) long. Don’t get them mixed up with the eastern diamondback rattlesnake which is a venomous snake.

Diamondback Water Snake - On Rocks
The Diamond-back watersnake is the largest watersnake in the US.

©Rusty Dodson/

What Is the Largest Sea Snake in the World?

When we open it up to freshwater and saltwater snakes, the sea snakes come into play. The largest sea snake is the yellow sea snake which can get to be longer than any of the snakes on our list so far. It can get to be 10 feet long!

They are not found in the US but live in Southeast Asia and in the northern Indian Ocean. These sea snakes do not come on land for any purpose, and many spend their lives in the deeper parts of the ocean up to 165 feet below the surface of the sea.

What is the average size of a Banded Watersnake?

The Banded Watersnake, also known as the Northeastern Watersnake, is a species of semi-aquatic snake that is native to North America. This snake is known for its distinctive banded pattern and its ability to swim in both fresh and saltwater. The average size of a Banded Watersnake can vary depending on a number of factors, including age, gender, and regional location.

Typically, adult Banded Watersnakes can grow to be between 24 and 42 inches in length, with a diameter of about 1 inch. Males are generally larger than females, with an average length of 30 to 36 inches, while females tend to be slightly smaller, averaging 24 to 30 inches in length.

However, the size of a Banded Watersnake can also be influenced by its location. For example, in the southern regions of its range, these snakes tend to be larger, while in the northern regions, they tend to be smaller.

Furthermore, the average size of a Banded Watersnake is typically between 24 and 42 inches in length, with males generally being larger than females. However, the size of these snakes can be influenced by a number of factors, including age, gender, and regional location.

What is the Largest Snake in the World (and is it a water snake)?

Green Anaconda Underwater
Green Anacondas spend much of their time in the water. They are the largest snakes in the world.

©Vladimir Wrangel/

The largest snake in the world is the Green Anaconda. And while it is not a water snake. it is actually a good swimmer. Green anacondas can get to be 500 pounds, so why don’t they sink?

They are able to spread their weight across the water and slither from side to side moving forward to skim across the water. Their eyes and nostrils are even located on the top of their head so they can see and breathe easily while they swim.

They actually spend more time in the water than on land! They do not live in the United States (except for maybe a few escaped ones in the Florida Everglades) but live in South America. Most are 20 feet long, but some can get as long as 29 feet, now that is a large snake!

Other Record-Breaking Snakes

Twin-spotted rattlesnakes are relatively small when compared to other rattlesnake species. Their typical size ranges between 20 to 24 inches in length, with an average length of 18 inches. Nonetheless, the largest recorded twin-spotted rattlesnake has grown to a length of 26 inches.

Conversely, the pygmy rattlesnake, which is considered the smallest rattlesnake globally, has a size range of 15 to 23 inches.

On the other hand, the eastern diamondback rattlesnake, known as the largest rattlesnake globally, can grow to a massive length of 7.9 feet, setting them apart from other rattlesnake species.

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About the Author

I'm a Wildlife Conservation Author and Journalist, raising awareness about conservation by teaching others about the amazing animals we share the planet with. I graduated from the University of Minnesota-Morris with a degree in Elementary Education and I am a former teacher. When I am not writing I love going to my kids' soccer games, watching movies, taking on DIY projects and running with our giant Labradoodle "Tango".

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