And it basically turned out exactly how you imagined it would -- well, not exactly, because he didn't get eaten. But he didn't beat the shark, either.
Phelps -- who agreed to participate in the spectacle because he loves sharks and, after earning 23 Olympic gold medals, a person probably just gets bored -- went head-to-head against nature's more fearsome predator on Phelps vs. Shark: Great Gold vs. Great White.
As the show opened, the deep-voiced narrator laid out the stakes of the race in the most over-the-top, dramatic introduction possible: "[Phelps has been] dominating the competition since he was a kid. 39 world records. 23 Olympic golds. But sharks don't care about medals. Out here, in the deep sea, Phelps is going to swim the toughest heat of his life… if anyone stands a chance in a race versus a shark, it's Phelps."
Before the 32-year-old sports icon took on the massive beast, he had to learn everything he could about all different kinds of sharks with the help of Dr. Tristan Guttridge. From learning about the different species of sharks to comprehending their different swimming styles, Phelps was given a crash course in how to beat the great white's speed.
At one point, Phelps' crew showed how much faster a shark is than a human by super-imposing a shark over one of his competitors in footage from one of Phelps' world-record shattering heats several years ago. Needless to say, the hypothetical shark won.
Phelps continued to try to increase his speed through the use of high-tech gear, including a monofin -- a specially-crafted set of flippers that were designed to mimic a great white's tail fin -- which shaved a full four seconds off his personal fastest time ever! But it was still insanely slow compared to a great white. Things were not looking good.
After swimming with a great white inside a shark cage off the side of a boat -- which the shark tried to rip apart with his teeth -- the crew finally got around to finding out how fast the massive predators can swim in a straight line in the ocean, about 100 meters in 36.1 seconds.
Despite what many people were hoping when they first heard about this stunt, the race didn't take place in a pool as Phelps and the great white raced in side-by-side lanes. The race took place in (very cold) open waters, and Phelps simply had to beat the great white's recorded speed over 100 meters.
Decked out with his monofin and a wetsuit designed to mimic shark skin, Phelps headed out to the ocean to see if he could do the impossible. And -- to make things more dramatic -- Discovery Channel digitally added a CGI great white shark swimming next to him the whole way.
In the end, Phelps actually did shockingly well. While the great white crossed the finish line first (so to speak) at 36.1 seconds, Phelps came in at 38.1 seconds. That's only a two second difference between a mere human being and the king of the ocean.
As it turns out, it's likely the ocean conditions that allowed the shark to win over raw speed. The freezing cold weather and Phelps' super-thin wet suit prohibited him from racing to his full capacity. Long story short: If they were able to get Phelps to race a shark in an Olympic pool, he might have won, as long as he didn't get eaten.
This isn't the only Shark Week show Phelps is participating in for Discovery's annual event. The athlete will also join Guttridge and Doc Gruber of the Bimini Shark Lab for another special, Shark School With Michael Phelps. Together, they aim to teach viewers about the oft-maligned animals and dispel many of the myths and misconceptions people have about sharks.
"I'm probably like one of the biggest nerds of sharks out there. I love sharks," Phelps said. "I swam with like seven [or] eight different sharks so far, some in the cage and most of them out of the cage, just kind of free diving, laying on the bottom. So if I have the chance to do more, I want to. It's just cool being able to watch those animals in their home. I think that's something that's really, really fun."