This crazy fin thing was developed by DARPA for scuba divers to swim 150% faster and with less effort than regular fins, helping to get places quicker and preserve oxygen along the way. Modeled after observing swimming habits of penguins and dolphins, it takes the strain away from smaller leg muscles, instead working the glutes and quads. It was intended for Navy SEALs (duh), but maybe one day we'll all get a crack at it. The shot above is newly released on CNet. After the jump is a schematic rendering from the original Popular Mechanics story.