Kicking Style

[Garth]

tell us how you really feel though...

 

[SolarStorm]

I didnt have a problem finning around, I just noticed my kick changed. Does anyone know where there is some research instead of marketing on the difference? In a past life I used to be a civil eng. so might be able to follow some of the fluid dynamics. More for interest than anything else. I still have my old trusty free frogs, I just fell for the line that I would not work as hard for the same thrust and bought them because they were shinney and new and we were excited without actually doing any research. Besides whats the point of buying something new if its not "different"

But now I am really currious if there was ever an article published on the actual measured efficiency.

 

[fnfalman]

I didnt have a problem finning around, I just noticed my kick changed. Does anyone know where there is some research instead of marketing on the difference? In a past life I used to be a civil eng. so might be able to follow some of the fluid dynamics. More for interest than anything else. I still have my old trusty free frogs, I just fell for the line that I would not work as hard for the same thrust and bought them because they were shinney and new and we were excited without actually doing any research. Besides whats the point of buying something new if its not "different"

But now I am really currious if there was ever an article published on the actual measured efficiency.

I'm a chemical engineer (MS ChemE). I fancy myself to know a thing or two about fluid mechanics.

Check out Atomic Aquatics website for how their split wings work. Atomic Aquatics - Before Atomic, there was no "best' in scuba diving

Most of these splitfins (from various manufacturers) took their inspiration from Nature Wing split fin design. Nature's Wing

I'm sure that these Nature's Wing people don't know squat about fluid mechanics but your typical DIR divers do.

 

[mdb]

The Natures Wing design uses the same principle as Bernoulli first discovered. A pronounced leading edge and a trailing edge which creates a pressure differential and provides thrust and power. Using top materials, such as all natural rubber, verus thermoplastics or other synthetics, results in a fin with power, control, and much less strain or effort.

There are several good versions of this technology now on the market.

We offer several models. Some prefer a stiffer fin, a bit more effort but more "feedback" and the ease of using with other kick styles.

It appears that fnfalman has a good take on it. A chemical engineer does know a bit about fluid dynamics.

 

[fnfalman]

The Natures Wing design uses the same principle as Bernoulli first discovered. A pronounced leading edge and a trailing edge which creates a pressure differential and provides thrust and power. Using top materials, such as all natural rubber, verus thermoplastics or other synthetics, results in a fin with power, control, and much less strain or effort.

There are several good versions of this technology now on the market.

We offer several models. Some prefer a stiffer fin, a bit more effort but more "feedback" and the ease of using with other kick styles.

It appears that fnfalman has a good take on it. A chemical engineer does know a bit about fluid dynamics.

Nah, I don't know nuthin' about no fancy fluid mechanics.

I prefer my ships to have paddle wheels too...to displace large amount of water and fight against currents and all that bad stuff that happen in the ocean. The propellers are for the fools who are sold on manufacturer's foofoo dust.

 

[Scott L]

Hydrodynamics isn't for everybody. Some of us prefer to work like a mule underwater.

Why have technical divers the world not over adopted their use? You have indicated in a post a few months ago you intended to pursue advanced nitrox decompression procedures training in 2010. I will check back with towards the end of the year to see if you have adopted a simple blade/paddle fin selection for that purpose.

Split fins probaly work great for the average recreational diver. No offence directed to the quality manufatures who produce them but for the fit divers who have technical diving aspirations blade/paddle fins dominate the scenery with a 90%+ market share...

 

[adm3745]

Split fins are more eficient but do not have the same amount of power. I'll go do a swim test in a set of 108's with a stage bottle with the splits and see what happens.

I am interested in the Scubapro Nova fins though. Waiting for more feedback till I buy a pair.

 

[Scott L]

Split fins are more eficient but do not have the same amount of power.

That statement is the very definition of an oxymoron. Fins are utilized to power/propel diver and equipment through the water. Sure split fins are esier to acheive greater fin kick cylces per minute but the problem is you are going nowhere fast. If shear ease of finning is the goal simply go without and one could simulate a hummingbird kicking underwater. Check and see what type of fins free-divers utilize, even longer basic paddle fins.

 

[adm3745]

I suppose it is then. What you just said is what I wanted to say but didn't. I Primarily dive Jets.

 

[mdb]

That statement is the very definition of an oxymoron. Fins are utilized to power/propel diver and equipment through the water. Sure split fins are esier to acheive greater fin kick cylces per minute but the problem is you are going nowhere fast. If shear ease of finning is the goal simply go without and one could simulate a hummingbird kicking underwater. Check and see what type of fins free-divers utilize, even longer basic paddle fins.

Well Vahalla, tell that to these guys:

“I am a US Navy SEAL and have been in the military for 12 years. I use fins in many different applications such as jumping from helicopters, airplanes, long surface swims, and extensive combat diver operations. I have tested the Bio-Fin in all types of profiles and environments and have found it to be superior in all respects to any other fin I have used.

The tests have been surface swimming on side, stomach, and back; against current, with current, 90 degrees to current; navigation dives with open circuit and closed circuit, [and] deep dives with open circuit. Other applications have been static line parachute jumps, military free fall night water RAMS parachute jump, and closed circuit scuba exhaustion dive. The Bio-Fins did better in all applications in areas of speed, comfort, ease of swimming, gas consumption (V02 max), deep dives and heavy current. I used different personnel from the military Special Forces community; SEAL, PJ, CCT, SF, RANGER, to accomplish these tests.”
- Tim Core MM1(SEAL/SW) United States Navy


“I am a U.S. Army Ranger and have been in the military for 8 years. I have used numerous types and styles of fins in various applications and I have been impressed with the performance of the Bio-Fin. I have tested it in different types of profiles and environments and I strongly recommend the Bio-Fin to all swimmers and divers, civilian and military.”
- David A Bucknam SSG USA, U.S. Army Rangers

The Executive Officer of the Special Forces Underwater Operations School stated “I have been extremely pleased and impressed with the performance of the Bio-Fin. I have tested it in all types of profiles and environments and have found it to be superior in all respects to any other fin I have tried. Normally to obtain optimal performance I have to switch fin types depending on whether I’m diving or surface swimming. The Bio-Fins deliver superior propulsion in both profiles and in heavy current. Most importantly to the combat swimmer, increased efficiency means less gas consumption, giving the operator more subsurface infiltration/exfiltration time, and so increasing the chances for mission accomplishment.”
- Joseph Diekemper LT United States Navy

SPLIT-FINS - REVIEWS AND PRESS