"I swam right up to this big structure and it looks like a building underwater. I felt a little bit of current. All of a sudden it got a little quicker and I said, 'this ain't right, this ain't right,'" Le Cun told WPTV.
Blake said Le Cun got "sucked in like a wet noodle."
Blake returned to the surface to get help from the duo's friends and family on a boat, while Le Cun was sucked down one of three 16-foot-wide intake pipes.
The diver said he was in the tube for about five minutes before he saw the light of the surface he would soon reach.
"All of a sudden it looks like a match, out in the distance, just the littlest bit of what you've ever seen. When it gets a little bigger, then a little bigger. Then all of a sudden just, poof, daylight. Fish everywhere, crystal-clear water the sun is shining and I'm like, 'is this heaven?'" Le Cun said.
Le Cun said he shouted for help and was assisted by a confused employee who asked how he got into the plant.
Blake and Le Cun said they did not see any warnings anywhere in the area, but an FPL spokesman said there is writing on the buoy reading, "stay back 100 feet."
Le Cun is now suing plant operator Florida Power and Light, alleging negligence for inadequate safety precautions.
"Nothing is more important safety at our St. Lucie Nuclear Power Plants, which is a reason that we have a protective over the intake piping. The diver intentionally swam into one of the intake pipes after bypassing a piece of equipment to minimize the entry of objects," FPL said in a statement.
Le Cun is not the first scuba diver to take a wild ride through the plant's intake pipes -- William Lamm had a similar experience in June 1989.
"I thought I was dead," the then-45-year-old told UPI in a 1989 interview. "It was darker than any dark I have ever seen. I tumbled and bounced all over the sides of the pipe."