Pervasive Fallacy about Split Fins

[ReefGuy]

aaaaaaaaaaararrrrrrrrrrrgggggggggghhhhhhhh!

 

[Adobo]

Fair enough, I agree wholeheartedly that you have to weigh all the factors. I just think it's important to not propagate myths. Your previous post sure seemed to have a lot of myths in it. You pretty much entirely ruled out the possiblility that split fins can go backwards at all and claimed they can't turn well (not that they can't turn "as well", just that they can't turn "well"). That post sure seemed to be propagating a bunch of myths.

No. There are a couple of people who claimed to be able to back kick and helicopter with proficiency in split fins. Even if I never have been able to do it myself, I still couldn't rule it out.

I've been in the same pool with the same twin speed fins on one or two occasions. I've also been in the pool with other split fins. Have I attained any level of proficiency with any split fin? Have I attained any level of consistent performance even closely resembling what I do without even thinking in Jetfins? Not even close. Does that mean that no one can?

In the end, it still comes down to the same thing - paddle fins are almost universally accepted as the fin of choice when one needs a fin that can move in forwards, backwards and pivot turn. And based on my personal experience (which now includes several pool sessions trying to figure it out for myself), it has everything to do with split fins' inability to do anything reliably and proficiently in any direction but forwards.

It's important when you're weighing the pros and cons of something to be honest to yourself and others. People tend to over-exaggerate to support their preference about split fins. Doing so only weakens the good points they have. You have good points about why splits aren't as good, stick to them.

People also tend to fixate on things that make absolutely no difference in the big picture.

Might I suggest you try it for yourself and bring back data from personal experience? The big picture becomes more clear in the water. And it's okay if you find that you change your mind as you collect more of your own personal data. I for one won't be challenging your sincerity or honesty.

 

[Temple of Doom]

People also tend to fixate on things that make absolutely no difference in the big picture.

I don't know how much experience you have yourself. Perhaps a little, perhaps a lot. If your website and personal profile is of any indication, then might I suggest a little more analysis in the water and a little less on the internet? The big picture becomes more clear in the water.

You may be illustrating your own point.

I don't have a lot of experience with either type of fin, which is why I wouldn't ever say which ones are better or worse (even after man-months with each in the water, I'd still be only qualified to make a statement like that for me). One thing I am good at is seperating fact from opinion, reading and assessing comprehensive tests, and addressing logical fallacies so prevelant in every one of these X vs Y debates.

I wonder if you find fault with any statement I've made to which perhaps your illustration of my lack of experience might have bearing on, or is it merely a straw dog argument in reaction to my pointing out your hyperbole?

Craig

 

[sohnje]

I found this post to be really interested reading all of the 'Controversy" surrounding the split fins. I would like to add a point that I think should be considered. The split fins creat less stress on the knee and ankle joints which is terrific for those of us with problematic joints. I found that the force needed to kick is much less than the regular fins. Interestingly enough, i was told that I could not travel as fast as those with regular fins, but thus far have not noticed any difference. A dive buddy switched fins with me once, and now there hooked. They too liked the lesser stress experienced when kicking. (but like stated before, you do need to kick differently)

 

[highdesert]

exactly the point I was making ... the flow through the split redirects water tip ward improving efficiency

Hmmm, I'm not sure if that's really the case. I don't really understand all the hydrodynamics of the split ...

In the case of a paddle fin, the side rails that run down the outsides of most fins act as an "end plate", preventing the fluid in question, in this case water as opposed to air, from spilling over the sides. That would be wasted energy. The end plates keep the fluid captive, so your stroke has something "solid" to push against. This is similar to the winged keels you see on racing sailboats, as well as the little vertical winglets you see out on the tips of many airplane wings. They both direct the fluid across the foil surface, rather than letting it escape unused.

In the split fin, you have a component of that same thing going on, the fluid moving down the length of the fin, but on any given fin thrust you also have the fluid converging across the fin, toward the split, and wrapping around the opposite side, creating the pressure differential that "pulls" you forward.

Or anyway that's my best guess.

 

[Adobo]

You may be illustrating your own point.

I don't have a lot of experience with either type of fin, which is why I wouldn't ever say which ones are better or worse (even after man-months with each in the water, I'd still be only qualified to make a statement like that for me). One thing I am good at is seperating fact from opinion, reading and assessing comprehensive tests, and addressing logical fallacies so prevelant in every one of these X vs Y debates.

I wonder if you find fault with any statement I've made to which perhaps your illustration of my lack of experience might have bearing on, or is it merely a straw dog argument in reaction to my pointing out your hyperbole?

Craig

Personal experience has bearing in that:
- you might find that efficiency going forward is not that important. It's not a race to see who can swim forward fastest. If it is, save some money and buy a scooter.
- you might find that you're joints dictate a need for fins that present less resistance.
- you might find that with your new drysuit, you need fins that are negatively buoyant. This might rule out a good number of the "new" fins in the market.
- you might find that you like photography. And having ability to turn left or right or go backwards consistently (not just every now and again) is important.
- you might find that you are one of the very few that can do other kicks proficiently with split fins.

You can discuss any topic you like in these forums. I'm just trying to point out that, in my opinion, you are barking up the wrong tree.

P.S. Be careful about the so called facts presented by magazines and manufacturers. You never know how much spin and agenda are behind them.

 

[fisherdvm]

This kind of remind me of the argument of using a 12 gauge slug instead of a 30:06 in heavy brush. All the tests will say they performe equally, or the 30/06 is better, but you can't change the mind of the folks who uses big guns in the brush.

Each favor their own.

 

[rakkis]

Would Chuck Norris ever use split fins?

Jack Bauer would :14:

 

[rakkis]

Preparing for a running giant stride.

No photoshop in this computer. phear my ms paint skills

 

[MikeFerrara]

When paddling a canoe it would be a totally different force exerted on the fin than it would with a flutter kick. Cave divers know that splits ARE inferior to paddle design fins when alternate kicks are used. I believe the OP is trying to get that point across that the splits aren't useless or evil in the right environment. Proper tool for the job. I use my splits in warm water, use the turtles in caves, cold water, wrecks and when silt is a big issue.

I would concede that split fins are not evil. LOL

I know other divers who use both so you aren't alone in that practice. At least two of them that I can think of right off the top of my head are cave divers that I have dived with who use split fins for some of their open water diving. I would describe them as divers who know how to use fins and while I haven't discussed this at length with them, I would guess they also know what each fin type is best at.