Split fin hate?

[Eric Sedletzky]

There’s another factor to all this that people may mot be thinking about, and that is the subject of drag, and weight on the diver in the form of equipment, or lack thereof.

So a freediver for instance is the most streamlined diver in the water. They align their bodies in such a way as to create the least amount of drag possible and they use very long very powerful fins to propel themselves. And because of the lack of drag they can wiz through the water with ease and the long fins do not have to push something with a lot of drag so they do not cause a lot of fatigue.

Now take a diver in an overstuffed poodle jacket with console hanging down pockets sticking out stuffed with gear, stuff clipped off and dangling causing drag and try those freediving fins. The resistance will be so great that the diver will tire out very quickly trying to use a fin that is that high geared. This is where split fins come in and in large part why they were developed, especially when the diver is out of shape and lacks leg strength.

Then take a tech diver who has an immense amount of drag in the form of doubles, stage bottles, more that likely a drysuit, and those split fins will lack the power to move that amount of weight and effectively push the diver with that much drag through the water. So there are vented fins or other stiff paddle fins that are better for that application and better finning techniques can be used that split fins can’t accomplish. Tech divers also tend to be in better shape than an occasional recreational vacation diver since there is more of a commitment to a health and strength protocol, so they can use a stiffer fin.

So we have three different types of fins for three different applications.

It would be like saying 4 wheel drive big mud tires would suck for nascar racing, yes I suppose they would. And dragster slicks would suck for offroad four wheeling, yes that’s true. And skinny little Prius hybrid tires would suck for top fuel racing, yes that’s absolutely true.
Different tools for different jobs.

 

[Lorenzoid]

Maybe the reason we need some flexibility in paddle fins is the need to sacrifice potential power for ease, since most divers don't have marathon runner legs? Maybe the sweet spot for recreational diving isn't a 'board,' but some argue it's not so far the other way as to warrant splits for everyone.

My guess is that this compromise--finding a "sweet spot"--is indeed part of the reason that fin blades have at least some portion that is somewhere between the extremes of completely rigid (like metal) and completely floppy (like the proverbial wet noodle).

Another part of the reason some floppiness is desirable may be the sort of hydrodynamics that @tarponchik was alluding to, where the fluttering motion that fish employ requires some flexibility in the fin. As tarponchik pointed out, it's probably a very efficient motion, thanks to millions of years of evolution. There may be no similar flexibility requirement for an efficient frog kick. If I recall, conventional wisdom is that a paddle-style fin is better for frog kicking, while a floppier fin is better for finning like a fish. But hardly anyone frog kicks 100 percent of the time, so we don't see fins that are completely rigid.

Still another possible factor occurred to me, which may be completely wrong, but here is my thinking. A very stiff fin is super-responsive and not forgiving of errant fin tip movements. You would have to be super-precise in the movement to avoid working against yourself. Anyone who has tried to learn the back-kick understands what I mean when I say if you're not careful when you retract the fins in preparation for the next kick you will undesirably propel yourself forward to some extent. I'm thinking the effect would be more pronounced with a completely rigid fin. My thinking is that even if a fin were to be designed for 100 percent frog kicking or something similar, a small amount of flexibility might be desirable to damp the effect of the occasional imperfect kick or lazy fin movement.

Lastly, a completely rigid fin would be difficult to walk in, and maybe even to hold one's balance standing up. It's already hard enough on a boat to shuffle in fins to and from the entry/exit. You'd really have to don/doff these in the water, which is often not practical.

 

[gassed]

Seems like many of us tend to view diving through the lens of a particular objective. I have a wide range of diving interests but spend most of my time slow cruising with the wife and taking photos. Splits are great for this endeavour.
I will probably change my fins as I delve deeper into tech/cave. That is very specific and I don't mind using specialized gear for a specialized task. When I finish my side mount training it is unlikely I will dive sidemount when diving with the wife. Why clutter up an easy dive? Could I? Sure, but why. So I will most likely use the splits on those dives.
At this point in time I have one bike. A mountain bike. I can ride tails and tarmac on the way to work. Would a road bike be better for going to work? Sure, but I can't ride it on the trails. So I guess I looks at my Atomic splits as my mountain bike of fins. They have never failed to get me from A to B. More importantly I am much more interested in what is between A & B than I am getting to B.
In the end I think my question has been answered. There does not seem to be hate for split fins. Just a current marking skew that will likely change again as time goes on. I remember when Computers and then Ai were also never going to work.......
Thanks for all the input. it's been fun watching this thread.

 

[Eric Sedletzky]

Seems like many of us tend to view diving through the lens of a particular objective. I have a wide range of diving interests but spend most of my time slow cruising with the wife and taking photos. Splits are great for this endeavour.
I will probably change my fins as I delve deeper into tech/cave. That is very specific and I don't mind using specialized gear for a specialized task. When I finish my side mount training it is unlikely I will dive sidemount when diving with the wife. Why clutter up an easy dive? Could I? Sure, but why. So I will most likely use the splits on those dives.
At this point in time I have one bike. A mountain bike. I can ride tails and tarmac on the way to work. Would a road bike be better for going to work? Sure, but I can't ride it on the trails. So I guess I looks at my Atomic splits as my mountain bike of fins. They have never failed to get me from A to B. More importantly I am much more interested in what is between A & B than I am getting to B.
In the end I think my question has been answered. There does not seem to be hate for split fins. Just a current marking skew that will likely change again as time goes on. I remember when Computers and then Ai were also never going to work.......
Thanks for all the input. it's been fun watching this thread.

All you have to do is look at the membership skew of scubaboard and you’ll quickly realize why there are so many derogatory comments aimed at split fins.
This site has a lot of DIR/GUE, Tech types, CCR, sidemount, etc. here, this is where they hang out.
Hardly any freedivers, and a large majority of the basic recreational crowd has moved on.
So you’re not going to get a lot of split fin love here.

 

[Lorenzoid]

Hardly any freedivers, and a large majority of the basic recreational crowd has moved on.

The "basic recreational crowd" doesn't spend their time talking about diving, online or otherwise. And if they did talk about it online, many of them would stick with Farcebook or whatever. They think about the subject a couple of times a year, once to plan their next dive vacation, and then a week before the trip. Most of us with the time and inclination to hypothecate about fins do somewhat niche kinds of diving, or are the kind of rare bird with both time and intellectual curiosity.

I'll add my belief that a lot of the really hard-core types ("DIR" or otherwise) don't frequent SB, either. They're out diving, and/or they're set in their ways and have no interest in discussing fins. I believe the discussions here are from a very thin slice of the diving population.

 

[Cert1967]

You’ll need to figure it out.
We’re not allowed to actually say anything because that’s bashing and I don’t want get in trouble for saying stuff.

 

[Bob Evans]

The "basic recreational crowd" doesn't spend their time talking about diving, online or otherwise. And if they did talk about it online, many of them would stick with Farcebook or whatever. They think about the subject a couple of times a year, once to plan their next dive vacation, and then a week before the trip. Most of us with the time and inclination to hypothecate about fins do somewhat niche kinds of diving, or are the kind of rare bird with both time and intellectual curiosity.

I'll add my belief that a lot of the really hard-core types ("DIR" or otherwise) don't frequent SB, either. They're out diving, and/or they're set in their ways and have no interest in discussing fins. I believe the discussions here are from a very thin slice of the diving population.

I agree, very very thin slice of Diving. Yet we have some of the cream of the top on the Scuba Board. I rather be here than on Facebook.

 

[NW Dive Dawg]

Yet we have some of the cream of the top on the Scuba Board.

Most definitely agree that there are some super great folks here who really know their stuff and provide tremendous advise, experience and value.........

But then there are also a few folks who seem to have deemed themselves as gods gift to everything diving and spend a lot of time judging and condemning any technique or equipment that doesn't fit into their narrow little worlds. Just sayn!

 

[BoltSnap]

doesn't fit into their narrow little worlds.

Prisoners of their own dogma also.

 

[drrich2]

One more sympathetic factor in the makeup of SB (I say this as a rec.-only diver with no professional or tech. training) is some divers may prefer to advocate for gear choices that can 'grow with you' into other niches in diving.

The big majority of divers never take a technical diving course, but if you start out with a BP/W setup, you'll already be familiar with a BC choice that works for recreational diving and can grow into tech. diving (though you might prefer having a separate rig for some of your diving - such as doubles, etc...). Or a dive computer that's tech. capable, not only rec.-capable.

So if they think splits are a poor choice for the kind of tight quarters precision diving I read tec. divers speak of, they may prefer paddle fins, figuring if you decide to switch to frog kicking, or do some light penetration, or simply want to avoid silting the bottom when finning along near it, starting with paddle fins might save you making an extra purchase later.

But if splits are a better fit for who you are and how you dive, go for it. Similarly, some people would rather just put on a jacket BCD and dive than be confronted with the flurry of choices informed shopping for a modular BP/W setup requires.