Can you hold your breath for more than 3 minutes? Don’t try. You’ll just hurt yourself. One man who can do it is William Trubridge. He’s a competitive free-diver. He swims unaided to depths many scuba divers won’t go.

He practices at Dean’s Blue Hole in the Bahamas. The calm water plunges nearly 700-feet straight down. These are perfect conditions for free-diving. He set the world record this year. Watch him dive 288-feet in 3:30. It’s impressive.