Here it comes...Split-fins or Full fins?

[PerroneFord]

Jerald,

I have no doubt people can do a frog kick in split fins. I dive with several divers who can do it, as well as helicopter. I even met one person who can backfin in splits. So I have no doubt that the poster finds he can do the kicks. That is not my point.

Split fins are forbidden in overhead training because they are indeed an entanglement hazard. You don't need to take that as my opinion. Merely go to any webpage of a training agency that does overhead training, and read their gear requirements.

Again, this is not "my opinion", it is the opinion of the many training agencies who do this type of training every day. After going through an overhead class with a diver in split fins, and watching her nearly tear the goldline apart, I am inclined to agree with the agencies.

If someone claims to be able to do alternative types of kicks in a certain type of split fins, why would you be doubtful? Do you have a reason to be doubtful of his claim? I know people who can frog kick in splits just fine. Do you doubt they can as well? And are you saying splits are a safety hazard because they have a smooth slit down the middle? That's ridiculous. Any fin can get line tangled around the buckles or the whole fin itself. Saying there is a safety concern with splits is absurd. You are merely looking for ANY reason to justify your opinion.

Sorry about hijacking the tread everyone.

 

[PerroneFord]

Just because you can go fast doesn't mean you have to.

I quite agree.

The fin's speed is an indication of the fin's efficieny and ability to convert kicks into foward motion. One of the previous posts implied the reason the split fins supposedly caused less cramping and muscle fatigue was because they sacrificed performance. A higher maximum speed would indicate that statement was incorrect.

The fin's speed is an indication of it's efficiency in ONE parameter. Speed while flutter kicking. I have yet to see ANY speed performance test of fins using anything other than a flutter kick.

The manufacturers claim the reduction in fatigue and cramping is the result of increased efficiency. The increased efficiency is supposed to come from the fin directing more water rearward, thus propelling the diver forward. As opposed to a non-split fin which displaces a higher percentage of water perpendicular to the fin.

The question is do we believe the manufacturer? If we look at what happens during a flutter kick with a blade, we can see that a large amount of water is directed downward. Since the split in the fin allows more water to slip past the fin and not be propelled downward, it stands to reason the split would in fact silt less. Whether that means it helps the diver move forward, I don't know.

Which brings me to another question. If the split fins direct more water rearward then a blade fin doing a flutter kick, wouldn't the blade fin kick up more silt then the split fin? I remeber the instructor telling us to try to remain horizontal in the water, which should result in the split fin disturbing the bottom less then a blade (assuming a flutter kick).

I do belive the blade fin, when doing a flutter, WOULD kick up more silt. However, it also is the reason the split fin is LESS efficient when doing a frog kick. The frog is particularly effective because it presents the width of the fin against the water for a very long stroke, and it's primary thrust vector is nearly directly parallel to the bottom. The flutter kicks force is directed nearly perpendicular to the bottom. So the very feature that allows the split to be more effective in a flutter, namely the ability to allow water to slip through the fin, hurts it in the frog kick because we WANT all that water being pushed backwards to propel us.

Again, just my thoughts, and I'd love to hear counterarguments.

 

[mdb]

Just because you can go fast doesn't mean you have to.

The fin's speed is an indication of the fin's efficieny and ability to convert kicks into foward motion. One of the previous posts implied the reason the split fins supposedly caused less cramping and muscle fatigue was because they sacrificed performance. A higher maximum speed would indicate that statement was incorrect.

The manufacturers claim the reduction in fatigue and cramping is the result of increased efficiency. The increased efficiency is supposed to come from the fin directing more water rearward, thus propelling the diver forward. As opposed to a non-split fin which displaces a higher percentage of water perpendicular to the fin.

Which brings me to another question. If the split fins direct more water rearward then a blade fin doing a flutter kick, wouldn't the blade fin kick up more silt then the split fin? I remeber the instructor telling us to try to remain horizontal in the water, which should result in the split fin disturbing the bottom less then a blade (assuming a flutter kick).

markr: You have summed it up pretty well. Apollo was the first company to develop this new technology. I was with the founder of Apollo when he first tested the Nature's Wing prototype fins. He came out of the water with a huge grin on his face. "This is it." he said. "I want to be first". He asked us to sell the molds to our Prestige paddle fins, they were a great version of paddle fins, high grade polyU, streamline design etc. I asked him why not have both. He simply smiled. The split fin design, when using the right materials, comes, as close as possible, to replicating Mother Natures design for Whales, Dolphins, Seals, Sea lions, and lots of Pelagic fish-a split fin. The paddle design is great for frogs and ducks. My first fins were Jet Fins, Voit duck feet etc. If you want low end torque and more feel just use a stiffer version of the split fin. At Apollo we make a very stiff XT-Extra Torque-model for that purpose. The most efficent-least effort, best performance, is still the original bio-fin pro. I like the XT's myself. I have been diving since 1972 and learned the long slow scissor kick, helicopter turns etc. My sons much prefer the pro model-"Why do you like boards on your feet?" is their usual comment. Divers are a great bunch, with many different opinions. Hope you have lots of safe diving no matter which fins you use.

 

[jeraldjcook]

I quite agree.

Since the split in the fin allows more water to slip past the fin and not be propelled downward, it stands to reason the split would in fact silt less. Whether that means it helps the diver move forward, I don't know.

Again, just my thoughts, and I'd love to hear counterarguments.

Sounds good. My only addition is that the design of the split fin is to channel water to middle of the fin, and the flexibility on the stroke/flutter then channels the water to the rear propelling you forward.

 

[TxHockeyGuy]

While I certainly don't have the experience of most posting here I can relate from my very last dive the difficulty my buddy was having doing a frog kick in splits. I think they were a scubapro brand of splits but I can't remember for sure. I personally have a pair of Aeris Velocity fins which seem to be a sort of a hybrid as they are very soft in the middle allowing the fin to bend as well has having holes for water to pass through (http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=AerisVelocityStrap). I can do a frogkick as well as a backward kick in these fins without a problem. Are these the best fins for that? I have no idea as I have never used any others but they work for me so I keep using them.

 

[pbgormley]

Nothing like an open mind... (usually, this flavor of one-sided pedantic opinion comes from someone that's never tried what they're flaming)

"Splits are easier to kick," because they're designed to work with an easy flutter, not a wide scissor... I tended to cramp with paddles, and found no increase in thrust over splits.

Splits aren't for everyone (just as paddles aren't)... Splits are fast, effortless, and avoid fatigue... Paddles are typically better for tight manuevering, and alternative kick-styles...

Obviously you'll find ardent advocates on both sides...

Try 'em for yourself... (and avoid any advice, as you put your gear together, that just dismisses one style of gear, or another, out of hand...)

Some good advice there BKP, agree with you on the cramping issue, I had the same problem so I went for the Scubapro Twin Jets, great kick action with them but as you say they're not for everyone.

 

[PerroneFord]

mdb,

Who is the Apollo dealer closest to 32301? While I cannot use splits in overheads, I most certainly would like to try them in open water. I have several regular buddies who dive splits (none Apollos sadly) but none my size.

Is there a try and buy deal?

 

[sasscuba]

Another vote for ScubaPro Jet Fins here!

 

[jeraldjcook]

TxHockeyGuy,

Do you remember what color his fins where? Different colors are different levels of hardness. The harder they are, the better for frog kicking. I can see how soft splits would not be ideal for the frog kick.

 

[mdb]

mdb,

Who is the Apollo dealer closest to 32301? While I cannot use splits in overheads, I most certainly would like to try them in open water. I have several regular buddies who dive splits (none Apollos sadly) but none my size.

Is there a try and buy deal?

PerroneFord: You keep an open mind.

In Florida Apollo stocking dealers are:
www.apollosportsusa.com/Dealers/Search_Results.php

Divers Den in Panama City, and Dixie Divers in Deerfield Beach, carry the most fin inventory. A lot of Divers Den orders are special military orders so they, sometimes ,do not always have a lot of stock. Dixie Divers stocks the whole range regularly.

Larry and Joe @ www.scubatoys.com in Dallas always stock and sell a full line of bio-fins.

Sorry we do not have someone in the Tallahassee area at this moment.