Split fins?

[Blackwood]

If you CAN'T see any advantages to using a split fin design, maybe this image of a dolphin's tail could help:

lol. What split fin looks and works like that?

 

[Scott L]

BTW, I don't think their "split-fins" have any more trouble with current than mine do.

Well that certainly settled the issue. Post these thoughts on GUE's, TDS's & DIR Explorers forums and attempt to convince tens of thousands of techinical divers that they have it all wrong with their blade and paddle fun usage. I need a good laugh today.

 

[vladimir]

Well that certainly settled the issue.

You sound skeptical. You must be one of "the non science, my great great great grand daddy understood things better crowd" who can't recognize rigorous analysis when you see it.

Post these thoughts on GUE's, TDS's & DIR Explorers forums and attempt to convince tens of thousands of techinical divers that they have it all wrong with their blade and paddle fun usage.

I am actually quite open to the idea that they have it all wrong. I'd just like to see some evidence more compelling than a picture of a dolphin's flukes and a pronouncement to that effect.

 

[rollerboi]

I guess I'm a little confused. On that dolphin's tail I'm just not seeing split fins. At all. Unless you mean that little notch?

Instead, I see these:

 

[BarrelRoll]

No no no, I'm sure the dolphin picture would convince me on split fins if:

-I had one leg
-The split was 1" long
-My one leg was the size of most people's waist
-I breathed through the top of my head and ate fish

Wait... Nevermind.

To the crowd that says, "I'm not pushing a bunch of gear through the water so it's no biggie", do you drive a car with bald tires because all you do is go to work so it's no biggie?

 

[elmer fudd]

A dolphins tail and fish fins look absolutely nothing like the split fins used by divers. If split fins were emulating either one, they would be several times wider and much shorter with almost non-existent splits.

Just from a physics standpoint, when someone swims with split fins, you can often see the silt rising off the bottom 4 or more feet away from them at almost a 90 degree angle from their position. Moving water at that kind of angle can in no way be an efficient way of providing forward propulsion. Another bit of nonsense I've heard is that the shape of the splits form water foils which aid in propulsion. Of course the problem here is that those foils aren't oriented right to provide any forward motion. They would explain those silty vectors coming off at 90 degrees though.

Now having said all this, I'm still not really opposed to split fins. My two regular dive buddies love them and they seem to get around just fine with them. I just don't think there's any real evidence to show that they are better and that the same benefits could probably be achieved more efficiently by just using a smaller, more flexible paddle fin.

 

[iztok]

No no no, I'm sure the dolphin picture would convince me on split fins if:

-I had one leg
-The split was 1" long
-My one leg was the size of most people's waist
-I breathed through the top of my head and ate fish

You mean tail not leg, right?

Median notch is about half of it length or so.

Again, not the leg it is basically tail.

The blow hole is really equivalent of nose.

 

[BarrelRoll]

You mean tail not leg, right?

Median notch is about half of it length or so.

Again, not the leg it is basically tail.

The blow hole is really equivalent of nose.

I somehow see this as mutating from fin physics to dolphin anatomy...

I don't know about you, but I put fins on the end of my legs, and since I have two of them, aaand a dolphin has one, and comparing myself to a dolphin is really not bright considering how much better than I am they are in the water (they don't even need tanks or wetsuits!)...

I was simply making fun of the idea that the concepts were anywhere close to related.

 

[orm]

haha can't believe this is still raging

 

[Blackwood]

You mean tail not leg, right?

Median notch is about half of it length or so.

Again, not the leg it is basically tail.

The blow hole is really equivalent of nose.

Anyone who's ever seen a dolphin swim can attest to the silliness of the comparison.