[ILDiver]

The split fins Whopperhead mentioned were cheaper split fins if I recall correctly. I have Scuba Pro Twin Jets. Split fins develop good power, they have drawbacks too. Scuba fins will allow you good torque, quickness and manuverability. Long blades give you faster straightline speed and more power to push you up from greater depths when you maybe negatively bouyant.

Check out Oceans in Action II, Manny talks about how and why he uses short fins. Fins are tools, the right tool for the job.

I prefer my long fins even in shallow water, I can cover more ground. When on scuba though, the longer fins take more leg strength and your pushing more mass and resistance in the water. There are plenty of scuba spearos that use long fins as well, for tha advantage of speed to chase a fish.

The straight short scuba fins were always like plywood strapped to your feet. With a fin you want the water to go off the trailing edge of the fin, but with a straight blade water spills off the sides. So not all of your energy is going into forward thrust. So fins with softer mid sections came out, then split fins. The goal was to push a majority of the water to the back. The split fins also feel easier to move. So less energy is used to generate the same speed. This feeling of less energy makes people feel like the are not moving like the were with the traditional hard plastic fins. But compared side by side, you can see that you really are moving just as fast or faster. I can move comfortabley on scuba with just kicking with my ankles.

With long fins, you get different flex of blades to find the best fin for your physical build and kick style. Most of the carbon fins have ribs on the edges to help channel the water to the ends of the blade and reduce the spill over.

This also reminds me, I need to find the thread on the monofin. A guy cut his to make a split monofin.

Good luck.