Days after Discovery Communications announced Nik Wallenda would take next take his high-wire act to Chicago to walk between two natgeochanneltall buildings, rival NatGeo said the holder of 15 free-diving world records will attempt to swim to a depth of 350 feet — deeper than the height of the State of Liberty — setting a new world record. On a single breath and with only his hands and feet to propel him, William Trubridge, 33, will attempt his dive into the abyss at Dean’s Blue Hole in the Bahamas.

Discovery has found ratings success with white-knuckle stunts. Wallenda’s walk across the Grand Canyon area of Arizona last year attracted more than 10 million live viewers. At its upfront pageant last week, Discovery did not set a date for Wallenda’s Chicago encore, except to say it probably will take place in November. The network also recently  announced that it will telecast California mountain climber Joby Ogwyn’s attempt to jump off the top of Mount Everest, the world’s tallest peak, in a specially constructed wing suit.

NatGeo’s dive special will follow Trubridge’s descent as it happens, from the last gulps of breath — in which he’ll try to swallow enough air to inflate his lungs to the size of watermelons — to his arrival at 350 feet below, where, NatGeo promised, ” a flood of nitrogen to the brain will cause disorientation and blurred vision,” to the final 66 feet of his ascent, when he’ll actually begin swimming in reverse “to keep his lungs from expanding too rapidly and bursting.” It’s at this final stage that an average of nearly 100 free divers die every year, NatGeo noted. It will be produced by DSP, an Endemol company, in association with Trium Entertainment and Apex Sports Agency.

“For more than 125 years, National Geographic has been about celebrating explorers who push the boundaries of human limitations. This will be a thrilling feat, and no doubt we’ll all be holding our breath right along with William as he attempts this almost unimaginable challenge,” NatGeo Channel president Howard Owens said in today’s announcement.