Rob Gronkowski is fearless on the gridiron, but the deep blue sea is a whole different beast.

Gronkowski appeared this week on the latest episode of the ESPN “SportsCenter” special “Hang Time with Sam Alipour,” during which the New England Patriots tight end swam with sharks off the coast of the Bahamas in what looked like an absolutely terrifying experience.

You could see the nervousness on Gronk’s face before he plunged into the ocean, and it only seemed to grow as several huge sharks swam right next to his face. Gronkowski called the experience both “insane” and “nuts” upon returning to the boat.

It’s been a strange offseason for Gronkowski, who considered retirement after the Patriots’ Super Bowl LII loss to the Philadelphia Eagles and skipped organized team activities as trade rumors swirled.

Swimming with sharks is a unique type of unsettling, though, and it probably makes a trip to Bill Belichick’s office feel like a walk in the park.

Thumbnail photo via YouTube screengrab