do split fins really help reduce air consumption?

[MikeFerrara]

rcohn...We're not getting anywhere...I think

 

[jonnythan]

MikeFerrara once bubbled...
rcohn...We're not getting anywhere...I think

I think the point being made is that neither of you know which kick is more efficient.

 

[MikeFerrara]

Maybe we should backup and define efficient.

 

[jonnythan]

MikeFerrara once bubbled...
Maybe we should backup and define efficient.

Let's say I'm doing a wreck dive at 50-60 feet in a lake on a calm day.

My buddies are doing a casual flutter kick, and I intend to keep up with them.

The question is: in your opinion (since there's apparently no produceable evidence either way), will I expend less total energy (and, I suppose, use less air) if I use a frog kick or a flutter kick?

Would the answer change if I were doing a cave dive? A wreck dive against the incoming tide? Fighting against the current in the Hudson? Why?

 

[MikeFerrara]

I say frog but I wouldn't dive that way. Especially for sustained periods at a given speed I will burn less air with a frog. I will also have more control. What do you think? That isn't how I would define efficiency. I would define it as moving at an acceptable speed, min effort, max control and ability to change direction and min silting. I want a propulsion technique that gives me the best combination of the above criteria. I have seen it with a frog but never with a flutter. Using a frog I can go from foreward to reverse in an instant, I can turn on a dime (even a 180 ) and I can get great power for suden bursts of speed. I can do a modified flutter at 50 ft/min using little but my ankles using little or no more air than when at total rest and get the control and have the ability to change gears without having to change positions or anything else in preperation. I don't think you can get that with a flutter.

 

[rcohn]

Mike,

Well, I think you started out with a nice simple (and testable) concept,

To reduce air consumption...
Propper propulsion technique (frog kick) - All else being equal the frog kicker will use less air than the flutter kicker.

nothing about silt, spinning in circles, bursts of speed etc. Just a basic issue, which kick, has the minimum air consumption. I'm assuming this is for a constant speed or distance traveled of course.

Throwing a bunch of nebulous criteria that aren't quantifiable into the mix just creates an ill-defined constantly changing objective, and that discussion will go nowhere. Unless you are finally agreeing that the frog kick may not have the best air consumption and need these additional criteria to justify its use?

Ralph

 

[MikeFerrara]

The original premis had nothing to do with the way we dive. My last post better describes what the real criteria are (or should be). What kind of diving do you do? The original question and the talk that followed sounded like a Rodale's review, which, of course, has nothing to do with diving! Examine any views you may have, which you haven't stated, against the criteria that I outlined and you will see why my position is what it is. I can be where I want in the water column and going the direction I want to go and the speed I want to go. Does that sound like diving? I could not do that by fluttering. If this sounds like a forign concept I totally understand. It often does to divers until I dive with them.

You want proof? Watch a flutter kicker and then watch a good frogger. My point will be obvious.

My original post listed several factors in reducing air consumption. You picked one the kick. The kick is but part of the package.

 

[jonnythan]

MikeFerrara once bubbled...
You want proof? Watch a flutter kicker and then watch a good frogger. My point will be obvious.

I've seen good flutter kickers and a couple of good froggers, and neither one seemed superior to the other to me. The flutter did maintain a smoother, faster forward motion, was very easy on air, and was able to position himself about the water at will.

I do have to say that just looking, the frog looks more inefficient and unnatural to me. I do understand it's best for silting prevention and I'm working hard on getting my frog kick down, but flutter still seems to be the way to go for open water cruising at a decent speed with minimum exertion. Split fins seem to be ideal for this, too. I firmly believe split fins are far more efficient than any blade fins.

I'd *love* to try a pair of force fins and see how that goes.. every time I hear anything about them, they're either twice as fast or twice as slow as everything else out there. "Feels like I'm not doing anything, but then I realize I left everyone behind!" to "Combat boots are better."

Too expensive to buy just for one try, but I'm intensely curious..

 

[rcohn]

MikeFerrara once bubbled...
The original premis had nothing to do with the way we dive. My last post better describes what the real criteria are (or should be). What kind of diving do you do?

It has plenty to do with diving I’ve done, but that’s certainly not the question here is it? You’re trying hard again to misdirect the discussion. How I dive has nothing to do with which kick or fin provides the best possible gas consumption

MikeFerrara once bubbled...
The original question and the talk that followed sounded like a Rodale's review, which, of course, has nothing to do with diving!

You read the original question and answered it without the slightest qualification. Only when questioned do you dredge up multiple issues about your opinion of what real diving is to obscure the fact that there is no support for your original assertion.

If you had ever performed any real testing or research, you’d understand that you must always select straightforward quantifiable issues to test. This is the only way any supportable conclusions can be drawn in any research. Rodale’s selects specific tests and tries to draw limited conclusions from them. They don’t (or at least shouldn’t) pretend to have definitive answers to all questions without a shred of supporting evidence. Their efforts attempt to increase real knowledge about diving rather than propagate myths. I’m not sure they always succeed, but at least they are trying.

MikeFerrara once bubbled...
Examine any views you may have, which you haven't stated, against the criteria that I outlined and you will see why my position is what it is. I can be where I want in the water column and going the direction I want to go and the speed I want to go. Does that sound like diving? I could not do that by fluttering. If this sounds like a forign concept I totally understand. It often does to divers until I dive with them.

Once again the original question was “do split fins really help reduce air consumption?” and your answer was “To reduce air consumption...Propper propulsion technique (frog kick) - All else being equal the frog kicker will use less air than the flutter kicker.” Simple question, simple answer. However when questioned you have no real support for this assertion.

You pass yourself off as an expert and always “know” exactly what the ”right” answer is to virtually any question, but when pressed are unable to support your answer. There is a large difference between an established fact and a very biased and potentially wrong opinion, but that is never even suggested in your posts.

MikeFerrara once bubbled...
You want proof? Watch a flutter kicker and then watch a good frogger. My point will be obvious.

When someone resorts to claiming something is obvious, you can almost always be sure they haven’t a leg to stand on.

When something is truly obvious it is EASILY proved. For example, it is obvious that dropping a weight belt when you are neutrally buoyant will send you toward the surface. The physics is a simple question of weight vs. buoyant force and if that fails to satisfy you, just try dropping your weights. Do multiple trials if you think the first time is a fluke.

If this discussion demonstrates little else, it shows that it is not obvious to many divers that a frog kick is more efficient or a better all around kick for all divers, than a flutter kick. You forget we aren’t all easily impressed newbies. I’ve watched good frog kickers and for whatever little my personal biased opinion is worth, I believe a flutter kick to be more efficient. I’m positive I have no quantifiable proof and this is only an unsupported opinion. But considering the people I’ve dove with and current teaching practices, I’m clearly not alone in that opinion.

Ralph

 

[kru]

Do split fins reduce air consumpsion? I think the answer is yes. They reduce fatigue and lactic acid build-up. That being said the difference for most is probably not that significant. I still prefer blades over split fins.
I did hear that Navy Seals are all using split fins now, but this may not be true.