Pervasive Fallacy about Split Fins

[in_cavediver]

Hi Bill,
This has already been referenced on this thread.
I'll give the link again. It appears to have been mangled on the first post, although it worked originally

http://www.scubadiving.com/upload/images/pdf/200510_scubalab.pdf

try this if the above just brings you to the top page of the mag

(see page 2 top right) They used divers pulling on guages tied to a pier as one of their tests.

They did concentrate on flutter kicks for most of their test, but they did evaluate alternative kicks as well​

This additional page has several years worth of tests. The link above is the 2005 results.

http://www.scubadiving.com/fins​

Splits seem to be on top of the scoring.​

PS. I agree, Backing up is a PITA, but I attributed that to my technique. One of my instructors who is a seriously technical diver uses splits for wreck diving and he swears that he can do any kick (including backup) just fine with his Scubapro twin jets. (he is just one person though, the referenced link is a measured study.)​

I looked through this and it was all flutter kicking. Seems a bit biased to use the one kick style favoring splits.......

 

[pwl]

there's a lot of discussion about split fins now ... do they reallly work and how do they make a difference in thrust. I can remember when the first Scubapro Jet fins came out in the 60s ....... at first divers made fun of the jets because "they had holes in them and looked funny".

absolutely they make finning easier:

- my wife has a total right hip replacement - her leg is weaker & using it a lot can make it sore

- she was using flat fins exactly like mine, but switched to split fins since they were heavier & helped with her floaty ankles

- she reported feeling much more comfortable & less tired after diving

- i eventually had to buy a pair of split fins to keep up with her despite her much weaker leg

so to me there's no doubt that split fins do a better job of propulsion. the ones we got are also more rubbery than our flat blade fins & a bit easier to manage on small boats.

there's also no doubt that if there's a line within 20m of where you're swimming, it will get tangled in the split

 

[pwl]

Thank you.
How come nobody else ever sees this? It's so obvious.

Sorry to say but I noticed that the only time a split fin works better than a "paddle fin" is when they are on someone who bicycle kicks.

YMMV.

i spend most of my time cruising along with frog kicks in splits with no trouble at all. i find i can do turns whilst horizontal, too (though i have no idea if they're really "helicopter" turns). back kicks haven't worked well for me - but that's almost certainly my technique as much as anything else. in any case i'm fairly sure i'm not bicycling.

it could be that my frog kicks, etc, are less efficient than they would be with, say, a jet fin - but it's not really an issue when doing cruisy slow dives looking at critters.

plus see my post above re injury: paddle fin = sore, unhappy. split fin = comfortable, happy

 

[under water]

I looked through this and it was all flutter kicking. Seems a bit biased to use the one kick style favoring splits.......

I think it is true that the battery of test was done primarily with a flutter kick, but the fins were also rated for alternate kicks as well. It works for me though, I use a flutter kick.
It's just data.. I'm still looking for the data that shows the superiority of paddles.. just can't find that yet. Lot's of opinions and many instances of dismissing data in favor of "This is what I think". I would even be glad to find a test done using only frog kicks, (which I believe are favored in cave environments to minimize disturbing the environment) similar to the ones referenced in this thread. Study after study shows no data that supports a conclusion other that splits are as good as or better than non-splits for performance.
As an engineer I like to have claims substantiated by designed testing and data. One race between two people is not a valid comparison. One persons preference to using one over the other is just that .. one persons preference.
Hey, I feel a poll coming.
But that would probably just be a popularity contest and not contribute to the data that we should be using to make these statements that we do.
So, Please, anyone, Where is the data that paddles perform better at any kick than a split. I am really interested in seeing that. No really, I am.
I would of course be kidding myself and everyone else who is banging their head on a wall by still reading this, if I thought for a minute that more data is actually going to change most people's mind.
Just dive and be safe..

 

[Lobbster]

splits are for people who cant use proper fins, eg. small women who dont have the leg muscles to use real fins. being a man i use cressi reaction's. there great fins.

 

[Diver Dennis]

I'm living part time in the Philippines right now and dive with a lot of "small women" who are instructors or just very experienced divers. None of them use splits and can dive circles around most of the men that dive with them.

I don't use splits nor have I tried them so I can't make a comment about their effectiveness.

 

[GA Under Water]

splits are for people who cant use proper fins, eg. small women who dont have the leg muscles to use real fins. being a man i use cressi reaction's. there great fins.

I feel it brewing. I give the women 10 to 1 odds.

 

[BKP]

splits are for people who cant use proper fins, eg. small women who dont have the leg muscles to use real fins. being a man i use cressi reaction's. there great fins.

Absolutely right! In fact, if you're REALLY a man, you don't need fins at all, 'cause your big fat man-feet will accommodate any kind of kick you might dream up... including the much revered finnis oralis...

 

[ONESPEED]

splits are for people who cant use proper fins, eg. small women who dont have the leg muscles to use real fins. being a man i use cressi reaction's. there great fins.

What exactly is a "proper" fin? And what are you overcompensating for?

 

[Diver Dennis]

What exactly is a "proper" fin. And what are you overcompensating for?

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