Charles Wieand and the 12-foot, 100lb anaconda were slithering around together in a pool in Califorinia.
Wearing nothing but a pair of cargo pants, the snake slithered and squirmed over Charles' body, with the reptile appearing at one point to lick his fingers.
Charles, from Columbus, Ohio, USA, said: "It was awe inspiring being able to swim that closely with an anaconda.
"The way it moved was breath-taking, it was so comfortable in the water.
"I wasn't overly worried as I know the snake's owner so was aware of its personality, however but you never know what can happen.
"I even managed to give it a quick hug."
Charles – who has relaxed on a lilo surrounded by alligators and done some bee keeping in the buff – is no stranger to extreme stunts, which he posts on his YouTube channel, Outdoor Adventures with Charles.
Despite that experience, taking a snake much more suited to being underwater than himself for a dip, presented a unique set of circumstances.
Charles said: "If anything goes wrong below the surface, you drown.
"As long as you know how to interact with them they can be pretty friendly.
"Having had freediving training I can hold my breath for upwards of three minutes, however I kept my time underwater shorter just for safety and to give her plenty of breaks in between diving.
Despite planning the stunt for a few months, Charles wanted to do it as a tribute for his freediving trainer Mike Kellenbarger.
Charles said: "Sadly Mike tragically passed away in a car accident in October.
"I had talked to him about what I was going to do and he called me crazy, but loved the idea.
"I wish he could have been here to see it.
"He was really my freediving mentor so I could not even have thought about trying this without him."
