Enlarge / Extreme sportsman Ross Edgley comes face to face with a great hammerhead shark in the waters of Bimini in the Bahamas. (credit: National Geographic/Nathalie Miles)

Ultra-athlete Ross Edgley is no stranger to pushing his body to extremes. He once ran a marathon while pulling a one-ton car; ran a triathlon while carrying a 100-pound tree; and climbed a 65-foot rope over and over again until he’d climbed the equivalent of Mt. Everest—all for charity. In 2016, he set the world record for the world’s longest staged sea swim around the coastline of Great Britain: 1780 miles over 157 days.

At one point during that swim, a basking shark appeared and swam alongside Edgley for a day and a half. That experience ignited his curiosity about sharks and eventually led to his new National Geographic documentary, Shark vs. Ross Edgley—part of four full weeks of 2024 SHARKFEST programming. Edgley matches his athletic prowess against four different species of shark. He tries to jump out of the water (polaris) like a great white shark; withstand the G forces produced by a hammerhead shark‘s fast, rapid turns; mimic the extreme fasting and feasting regimen of a migrating tiger shark; and match the swimming speed of a mako shark.

“I love this idea of having a goal and then reverse engineering and deconstructing it,” Edgley told Ars. “[Sharks are] the ultimate ocean athletes. We just had this idea: what if you’re crazy enough to try and follow in the footsteps of four amazing sharks? It’s an impossible task. You’re going to fail, you’re going to be humbled. But in the process, we could use it as a sports/shark science experiment, almost like a Trojan horse to bring science and ocean conservation to a new audience.”