When you're designing a product that helps someone race through the water, it only makes sense to draw your inspiration from the ocean's resident experts. So you might be surprised to hear that Speedo closely based the design for its new Nemesis fins on humpback whales instead of sharks or dolphins. Either way, it's a good thing Mother Nature doesn't hold any patents.
There's not a lot of specifics on how the hydrodynamics work, but Speedo claims the lines of ridges and holes on the Nemesis fins helps them displace more water as a swimmer kicks than with a traditional fin design, which results in more propulsion with less effort. And if they're good enough for propelling one of the largest creatures on the planet, there must be some sound natural engineering behind that unique design.
The $US40 fins are also made from EVA foam instead of rubber, so they will float to the surface if they accidentally fall off, instead of sinking to the depths of the ocean. As an added bonus, you can pretend that's a blowhole up top.[Speedo via Outside Online]