The flipper's scalloped edges (or "tubercles", for the marine biologists in the audience) are reminiscent of a humpback's pectoral fins, giving you more surface area off which to push. Meanwhile, the grooves up top guide water toward the blow valves on the side.
To top it off, the whole thing's molded from EVA foam, which is meant to make you more streamlined by keeping your feet and hips elevated in the water. You may not look like Michael Phelps, but you'll definitely have his swimming posture! Maybe.
Speedo's Nemesis Fins are currently available to pre-order for about $40.
Gianni Jaccoma is an editorial assistant for Thrillist Travel. He's not the strongest swimmer in the world, nor is he a whale, so these fins are a godsend. Follow him into the water on Twitter @gjaccoma