Michael Phelps is the greatest human swimmer of all time, but if you put him up against any random great white shark, he's chum.

That is, unless he gets a special flipper for his feet that will mimic the function of a great white shark's tail fin. Which is exactly what he gets in this clip from Phelps Vs Shark: Great Gold Vs Great White, seen here via Entertainment Weekly.

In the special, which kicks off Discovery's annual Shark Week programming, Phelps will race a great white shark. It's pretty simple. Unfortunately, he won't be in the water with the shark, but his numbers will be measured against the shark's. And this is one race the all-time Olympic gold medal record holder is not favored to win — great whites can swim about 25 mph; Phelps topped out at 6 mph at the height of his powers. So he needs all the help he can get.

Hence the monofin, which some engineers are explaining in the clip.

"For 20 years of me spending time in the sport of swimming and training, this is going to make me the fastest? Just putting on this fin is going to make the fastest?" Phelps says. "Should have just done this all along. What the hell was I thinking?"

Phelps Vs Shark: Great Gold Vs Great White airs the first night of Shark Week, Sunday, July 23 at 8/7c on Discovery.