Split fins

[SelkieDVM]

FWIW. . .

My brother is a professor of engineering at Duke who studies fluid dynamics. He is also an avid diver. I posed the question to him a couple of years ago regarding any possible advantage to splits. From a hydrodynamic standpoint, he explained that they are not as efficient as paddles.

Later when I became involved in another thread on this topic I querried him again. His response was that, "They place the shed vortices in the water in a orientation that serve no useful thrust purposes." He sent me copies of three studies. The files were very large (and incomprehensible to me) and I subsequently deleted them. However, he also said that paddles were not much better and that all fins are not very efficient in general (at least the ones used by humans).

So I can't supply references but it was good enough for me. My take is you should use whatever feels right for you and the kind of diving that you do. Me, I love my Jets.

 

[firstdive2005]

You either aren't using the fins properly, or you have weak legs. Chances are, it is the former.

It wouldn't surprise me if you got craps trying to flutter kick with paddle fins -- while they work for flutter kicking, they are optimal for non-silting kicks such as the frog, modified frog, modified flutter, back, or helicopter turn.[/quote]

It always amazes me how people can diagnose problems here and think they are right. While I have no doubt about your dive skills, i dont think you can say what you said to him based on your dive skills. I have been plagued by cramps my whole life. My leg strength is above average. I stretch everyday. I waterup. And I know my chemical comp is fine. When I point my toes, for some reason after awhile my calves cramp. I have great skills with kicking, this is not my diagnoses. My craps NEVER come on when I use the splits. I use my Jets when I know I will be doing minimal straight kicks. I mainly frog with them. So dont know why anyone else cramps, the docs even have a tough time fixing this issue with people. O one more thing there is a drug I can take that always helps with not getting these cramps. I found it while my mom was alive. She was getting cramps. So I went to my doc and asked if it would work for me. He said we can try. I got an answer from dive docs on it an it is a go. I dont like using chemical trreatment, but it is widely used for other reasons also, I will not say what it is here. Get a doctor to tell you what it is. I generally take it if I will be doing a long swim with my Jets.

 

[J.R.]

My brother is a professor of engineering at Duke who studies fluid dynamics. He is also an avid diver. I posed the question to him a couple of years ago regarding any possible advantage to splits. From a hydrodynamic standpoint, he explained that they are not as efficient as paddles. ... . However, he also said that paddles were not much better and that all fins are not very efficient in general (at least the ones used by humans).

Yea... but he's an *ENGINEER*...

Probably right... still love my Twin-Jet Max... (... humm... come to think of it I also love my old Jet Fins... wierd.)

 

[SelkieDVM]

Yea... but he's an *ENGINEER*...

Probably right... still love my Twin-Jet Max... (... humm... come to think of it I also love my old Jet Fins... wierd.)

Yeah, we'll he's also left-handed and was dropped on his head as a baby. Still love him, though.

 

[pidgiepoo]

I had knee surgery (meniscus removed) and was having pain when using my Cressi frogs. Someone recommended these to me when I first bought my gear, and I'm not sure they were the right fins for me. Anyway, they were ok, until after I had the surgery, and the pain got worse. I then bought split fins and have never had knee pain since. Glad I read this thread because I can see I need to change/improve my kicking techniques and do bicycle exercises to improve my leg strength.Thanks to the Op for starting it.And a special thanks to Sparticlebrane for the videos on the helicopter turn...granny is gonna perfect that this summer!

 

[Hatul]

As far as mechanical efficiency goes, I've seen conflicting reports.

Personally I use Force Fins Pro for comfort. I tried the Apollo Biofins and found them very uncomfortable, and a friend's Atomic split fins. The Atomic were nice, and if I were buying split fins, I'd probably get those.

Adam

 

[firstdive2005]

Yeah, we'll he's also left-handed and was dropped on his head as a baby. Still love him, though.

O no it's all too clear now, thats why I like the splits. I'm left-handed.

 

[Seiler]

For me personally Splits are only way to go. Apollo Bio Fins are my personal favorites. I just pick up a pair of Atomic. For the past number of years in tests the splits always win in most thrust generated. I think it is a Ford v Chevy debate.

 

[psychocabbage]

For me personally Splits are only way to go. Apollo Bio Fins are my personal favorites. I just pick up a pair of Atomic. For the past number of years in tests the splits always win in most thrust generated. I think it is a Ford v Chevy debate.

I just got my Apollo Bio this last holiday season and love them. I did have the TUSA Xpert Zoom black (Stiffer) and definately feel the difference btw these two. I did not like paddle style fins at all.. Not even a little.

I will say I am a bicyclist and flutter kicking is just more natural to me as I can do it all day long.

I originally went with the TUSA splits because the wife is a very fast swimmer and was using paddle fins.. I figured with the splits I could at least keep up when we did our shore dives. I was right.. I could be relaxed and keep her withing viewing distance and when needed, I could accellerate and catch her easily.. With the Bios, wow! Huge difference.. Love them.
I did not get the stiffer material ones.

 

[FishOutUvH2O]

Since I grew-up in Navy housing in Coronado, CA (home of Navy SEALs training) my first fins as a kid were Jets and Duckfeet, because they were everywhere and free. I naturally learned that you could really get moving in Jets with a normal, pretty wide, average paced flutter kick. When I learned to SCUBA (not to long ago) I switched to splits (Scubapro Twin Jet Max). What I quickly found-out was that doing a normal flutter kick the same way that I did in the Jets resulted in me exerting a lot of energy and going nowhere fast. I thought that splits were the worst idea ever. I found this hard to believe, so I started experimenting.

What I found was that if I cut the width of my flutter kick in half, maybe even down to as much as one-third, I could really get some power out of these things without really expending a lot of effort. Unfortunately, I also found-out that old habits are hard to break. The moment I would start to fight a heavy current, I would naturally widen my flutter kick. This of course resulted in me going nowhere fast. So the lesson I learned was that splits *can* be a good fin, but you have to experiment with your kicks to find-out which way gives you the best pay-off.

Just to be clear, I'm not taking the position that splits are better than paddles. That's an individual choice that will depend on which type feels the most comfortable to you. I'm also not saying that paddles are better than splits at other types of non-flutter kicks (frog, back, scissor, etc.). Again, I believe that if you're comfortable with whichever type of fin you're using you'll be able to learn to do just about any kick style just fine.