Largest venomous snake in U.S. spotted swimming in waters off Florida Keys

The captain of a charter boat who was fishing off the Florida Keys spotted a deadly species of rattlesnake swimming in the ocean.

Instead of finding fish, Ted Wilson found a five-foot Eastern diamondback snake, which is the largest venomous snake in North America, according to National Geographic.

Wilson took cellphone video of the snake, and told WSVN that it was swimming toward the boat and "appeared to be island hopping." 

“I’ve never seen a rattlesnake in the Keys, much less a five-footer swimming in the middle of open water,” a person can be heard saying in the video. It has been viewed more than 150,000 times on Facebook.

The Eastern diamondback snake is a type of rattlesnake that can grow up to eight feet long and weigh up to 10 pounds, according to National Geographic. Luckily, antivenin is widely available in the country and bites are rarely fatal -- but extremely painful.

Most diamondback snake bites are a result of humans trying to taunt or capture it. They are found throughout Florida -- even in the Florida Keys, according to the University of Florida.