A 10- to 12-foot great white shark was spotted on Alligator Reef off Islamorada Saturday, circling a charter snorkeling boat for about 30 to 45 minutes.
Captain Chris Muller got into the water to shoot video of the shark as it swam by his boat around 3:45 p.m.
"I've never seen anything like this in my life, especially not in the Keys, and I've swam with a lot of sharks," Muller said Sunday.
Muller had a charter of 13 people, mostly exchange students from places like Thailand and South Korea.
He had just put the snorkelers in the water and went into his wheelhouse while his mate, Greg Schlosser, watched the swimmers. A few minutes later, Schlosser came into the wheelhouse and said there was a great white in the water. He thinks it was a male.
"I said, 'there's no white out there,'" Muller said. "Sure enough, there it was. He was big."
Muller and Schlosser quickly got the customers back aboard the HappyCat. He said they were freaked out at first, but then became excited as they watched the shark swimming.
Schlosser was the first to go in the water to confirm the species. He also shot video of the fish.
Muller notified an arriving dive boat of the shark before taking his charter to the Alligator Lighthouse to swim.
"They had a good time and weren't afraid to go back in the water," Muller said. "The shark didn't follow us. He stayed on the deeper, southern end of the reef."