OK, let me then add:
- Splits can be seen as representing a "smaller gear"....if paddle fins were like a 42 x 18 gear (somewhat hard to allow high speed without really fast pedaling rpm/cadence) then the splits could be likened to a 42 x 25 gear...a gear used for climbing steep hills without trashing the leg muscles---letting less work be done per revolution -- this lets a cyclist climb a steep hill he could not climb in his larger 42 x 18 gear....the splits can push a non-hydrodynamic diver with tons of mass( stages, doubles, hoses and bc dragging everywhere like crazy) with less effort per kick cycle, but requiring many kick cycles to be equivalent to one kick cycle with the Jet fin. If there are no currents to beat, and no paddle fin wearing divers, or no hydrodynamically slick divers to keep up with ( buddies) , then you might say the splits would be great, assuming the diver is in no rush to travel a few hundred yards. If there is a need to travel at the speed of a jet fin wearing diver ( due to current, for instance), then the split fin diver will first begin running up a large cardio load, then higher breathing rate, and on needing more speed, the split wearer will not have sufficient kick turnover speed to acheive this--or will first run out of aerobic capacity for the effort.
I might disagree with this. There are LOTS of studies, some even by independent folks who don't have an interest in the outcome, showing that many splits are faster than most paddles. You can search the forums if you like. Splits do tend to like a modified flutter, with smaller kicking strokes. This smaller stroke, which is easily accomplished by bending more at the knees and less at the hips, along with split fins' lower resistance, allows a high kick frequency, but with much less total energy output per kick cycle. So, it is not likely that the user will run out of aerobic capacity just because he/she is kicking more rapidly. Different efforts, different muscles, etc.
As for current, it's a non-issue. If the diver can go faster in static water, he/she can go faster in current. The fins don't see, care or notice the fact that the water is moving relative to the bottom, only that the diver is moving relative to the water. I used to worry about this current thing as well, but 2 years ago, someone on this board set me straight. I modified my kicking technique, and problem solved.
Now, if a kick technique is used that is less suited for either type of fin, then the performance of the fin will be reduced. So, it is important that each diver learn what type of kick is most appropriate to the individual fins being used.
As for another poster saying he rescues lot of people in splits, that's just silly. The fins don't cause divers to need rescuing. What, people with paddles don't need rescuing ever?
Some anecdotal evidence. My brother is 7 years younger and in a whole lot better shape than I am. He's about 50 pounds lighter and runs 10k's (or longer) somewhat regularly. I do bicycle a bit for fitness, but I can't hold a candle to him. He, however, uses paddles. Sorry, I forgot which ones. I can swim away from him with my bio-fins if I want, regardless of current. We use the same tanks and same bc's, so there isn't much difference in streamlining. In fact, with my extra bulk, I am probably creating more drag.
I do agree that splits are not as effecient or easy to use with kicks other than flutter variations, although they can be used with other kicks.
Please, I am not trying to start or continue an argument, but there is real evidence and a lot of experience that shows that splits are just fine in currents and don't make people run out of breath.
Mike
