SEALs don’t like split fins either.

[M-Cameron]

What makes you think that they are team 2 members?

The link I also posted credits them to group 2

 

[PBcatfish]

The link I also posted credits them to group 2

Thanks, I missed that

 

[dmaziuk]

When I look at the way that split fins pronate when they are stressed, it is apparent to me that energy is being wasted as the two halves of the split produce opposing forces towards the center of the fin

... instead of twisting the blade and making it slide sideways. That's the trade-off that makes them easier on the joints: the joints don't have to work as hard to counter-act that.

I guess you could probably fine-tune them by moving the zip tie up and down the blade.

 

[John C. Ratliff]

I conducted some interesting experiments some years ago concerning a flat blade fin, a split fin, and the "scoop fin" design I developed.

PlanaPlus Experiment by John Ratliff, on Flickr
For my March 12, 2010 tests, I used three identical fin sets, but one was a flat blade, one a split fin design (self-made split), and one was my scoop design. I looked at yards per stroke, distances per unit of time, and strokes per mile. You can see the results below, but the flat blade had on average 30.8 strokes per 50 yards, the split 30.2 strokes per 50 yards, and the scoop design 29 strokes per 50 yards. This works out to the flat blade having an average of 1084 strokes per mile, the split design 1063, and the scoop design 1021 strokes per mile.

From 1967-71, and then from 1972-77, I was a USAF Pararescueman. I used several fins during that time, including the original Duck Feet fins, Scubapro Lightning Jet Fins (which I liked), and my design of scoop fins. Here you can see me using the Scubapro Lightning Jet Fins during a Unit Training Activity (UTA) for a water pickup using a HH-34 helicopter in 1973:

HH-34 Water Pickup by John Ratliff, on Flickr

If you open the Excel file below, you will see three tabs, and the first has the results from my above tests. The second and third shows results for a number of different fins. If you look at the second tab, marked "Fin Trials 3-13-2010," you'll see that the Apollo Split Fin (full foot) was on par with the USD Rocket fin, and my scoop-modified White Stag Super Stag fin.

'Hope this helps the discussion.

SeaRat

 

[Diver below 83]

What makes you think that they are team 2 members?

The original article I took the pictures from stated they were team 2

 

[Lostdiver71]

I noticed the camo freediving suits too.
I did a fin test once at the Sonoma State U pool with several types and styles of fins. My least favorite were Nova’s. I used black Apollo Bio Fins and liked them better than the Nova’s. I used Scubapro twin jets against the Apollo’s and had mixed results which means they were pretty close to equal. Regular SP Jets provided more power but wore me out faster. Mares Quattro’s had a “dead” spot at the directional switch that I didn’t like, and freediving fins blew them all away. All kicks were standard flutter kicks, or as some people call them scissor kicks.
No frog kicking was used for the test.

Those guys are in better shape than most NFL or NBA players. They could absolutely torture Jet fins and make them beg for mercy if they wanted. Those guys have some serious horsepower and stamina.
I’m sure they test fins a lot and tinker with stuff to tweak it the way they like it. Maybe one of them figured out that zip tied Apollo’s work pretty damn good everything considered, and it caught on in their tight knit group.

Those are not Apollo's they are ScubaPro TwinJet Gorilla fins, I have been using the same fins since they came out! A majority of my diving is drift diving and I have used them many times when towing the float ball for a commercial dive operation with zero problems.

 

[scrane]

I like split fins. If it weren't for split fins those of us who dive Force Fins would get the abuse.

 

[tursiops]

As said, I and my wife did use freediving fins in caves, in Sardinia, for more than 10 years. But of course ours were not really the longest ones (which can be well beyond 1.20 meters), our owns are approximately 90 cm.
At the beginning we were touching with them everywhere. But it was very instructive: we did learn to always stay with completely stretched legs, perfectly horizontal (at Capo Caccia what really matters is not to damage the coral under the ceiling, the bottom of the cave has nothing which can be damaged).
We laugh when we see those so-called "cave divers" staying in this ridiculous position:

View attachment 559266

See the long fins (more or less as our ones), but the legs are bent (with more than 90° angle at the knee) and arms are stretched forward-down, instead of staying close to the body.
We did always correct our students when seeing them with bent knees and partially stretched arms...
It seems that this is how they are trained, nowadays, in "cave diving" courses. And frog kicking with bent knees, which is really terrible.
Doing this, they would destroy the red coral in Italian caves. It takes 30 years to grow again...
Here you see the typical "ceiling" of our caves:
View attachment 559267

You probably ought not to be so critical of cave divers; the kicks and body positions are compliant to the specific environment. With your long fins and the kick you describe you probably would not even be allowed in some decorated caves where breakage of fragile structures can never be repaired. See, for example, some of the videos of Brian Kakuk in the caves of Abaco, in the Bahamas.

 

[Hoag]

Most dive lockers have a ton of fin choices.

In our locker I have seen Jets, rockets, twin jets, frog fins, etc.

Remember during combat swimming we aren't using good trim or a nice frog kick. We are flutter kicking Kilometers to a beach or ship, wearing a ton of gear and toting rifles.

(I am not a SEAL, I am a Marine who does alot of amphibious stuff)

Thank you for your service.

 

[Angelo Farina]

With your long fins and the kick you describe you probably would not even be allowed in some decorated caves where breakage of fragile structures can never be repaired

True.
I dove in Grotta Giusti, Monsummano Terme. Here fins of any type are entirely forbidden...
Long fins and the horizontal scissors, instead, are perfect in Capo Caccia, where the delicate red coral grows upside down, under the ceiling.
Here instead people bringing their fins up, bending their knees, are usually invited to exit.