Well, this topic was a very interesting one for me when I started diving eons ago (back in October
)
I own and use the TUSA xpert Zoom split fins myself.
What my research has found:
Split fins generate an average of 27% more thrust OR require 27% less effort to utilize.
The kick is a small Fluttter kick as opposed to a wide cross kick.
Split fins muct be used totally submerged else they are about the same as swimming with no fins at all.
and finaly; You tend to pay more for Split fins.
What my experience has taught me:
Split fins are excellent if you want to 1. reduce fatigue, 2. reduce air consumption, 3. reduce muscle crampingand gain 4. additions to your HORIZONTAL movement and Free Diving Descent.
Split fins are terrible if you are looking for 1. position stability (IE: For hovering in one spot to take a photograph underwater.), 2. Surface swimmming, 3. Turn manueverability using frog kicks, 4. Controlled emergency swimming ascents (I'd run out of air everytime I tried to reach the surface from 33 feet in this excercise while wearing split fins)
Some hearsay: People with long time experience with Paddle fins have the most trouble making the transition to Split fins. Therefore, the best people to use Split fins are people that learn on Split fins from the start.
However, if I had it to do over again, I would have done all my certification dives using Paddle fins instead of Splits as the extra "support" is essential in allot of the skills you are required to perform to check out.
Hope that was helpful and informative.
SpyderTek