NOAA prohibits split fins

[Soggy]

Wonder if you can duct tape the split, and so they work better in current? It's about time that they make split fins with zippers. You can zip them up underwater when you need to?

I need to get a patent on zipperred split fins.

If you make a bunch of outrageous claims and provide "studies" regarding their effectiveness, I bet you could sell thousands. Really, I think you have a good idea from a marketing perspective.

 

[chickdiver]

I would not be surprised...

Evaluation of fins used in underwater swimming.
Pendergast et. al. Undersea Hyperb Med. 2003 Spring;30(1):57-73.
RRR ID: 3936

In talking to Dave about this project, he also looked at force fins and split fins with a "bicycle" type kick. The different kick did show an improved efficiency in those fins. As a bicycle kick is not a proper or even efficient method, it is not reported in the article above. The paper above was tested with a proper flutter kick. (Another interesting note was that you could improve VO2 efficiency with split fins by using duct tape on the split.)

As stated above...

because they are crap.

 

[pilot fish]

I wasn't using an obscure definition of citation
http://dictionary.reference.com/browse/citation

Please provide information referencing your source. Where did this information come from, who authored it, when was it written, etc, etc...

No, I realize you were not using an obscure term, or one I'm not familar with, but I was puzzled since I quoted NOAA and you could to a search on there, which I see one kind diver has linked for you.

 

[under water]

Really,
Please read the report.
http://www.uscg.mil/ccs/cit/cim/foia/Healy/HEALY_FAM.pdf
This was complete screw up from the get go.
Inexperienced divers wearing too much lead with no real dive plan, not hooking up their BCs to air and everyone drinking who was supposed to be watching them to name just a small number of things they did wrong.
The split fin thing is a complete red herring and the ONLY reference to it in the report was this on page 19 of a 26 page report.

Several pieces of equipment for the dive were non-standard, missing or not functioning properly:​

o Both divers wore buoyancy compensator devices not attached to an air supply;​

o LT Hill was outfitted with two secondary regulators, one with an air supply and the other without an air supply;​

o Both divers wore a single steel-100 tank with standard breathing air. Diving
under the ice or in cold water (water temperature below 37 degrees
Fahrenheit) must be conducted with a "redundant SCUBA system" which is
defined as twin tanks, per the Navy Diving Manual. The seawater temperature
for this dive was 29 degrees Fahrenheit.
o Both divers wore split fins designed for high speed, but which provide
minimal thrust in heavy diving. Split fins are not considered appropriate for
heavy diving, but rather for light diving and snorkeling.
o The divers wore their dive mask straps under their drysuit hoods, not
considered a safe practice in cold water.
o BM2 Duque's AGA regulator was missing a protective guard.​

This is just a small sample of what they did wrong. Read the report. Throwing in an opinion about split fins, unsupported by any data is really a shame because there is so much more to take away from this incident.​

 

[pilot fish]

As stated above...

because they are crap.

Do you think they're crap, Chick? I have my doubts too, since I was the only diver left behind when turning around a pinnacle into current on Dominica once. After discussing this with other divers, and ScubaPro, I realized I was using the improper strong, deep, single paddle fin kick, which is what I was used too, and not the proper, rapid, shallow fin kicks required of splits. I'm still not convinced though that I'm safe with split fins in ALL conditions. I can tell you, they are great with mild to no current and require little leg action, but that might be true of all fins under those conditions?

 

[Diver Dennis]

Ah yes. Facts. Thanks Frank.

 

[pilot fish]

Frank, that is very helpful. Thanks. What you quote does shed more light on this but I still wonder if the splits did contribute to ANY degree in the accidnet?

I see that you have bio and Scubapro Jets - are the jets wide, single paddle fins? What determines which of those fins you use?

Really,
Please read the report.
http://www.uscg.mil/ccs/cit/cim/foia/Healy/HEALY_FAM.pdf
This was complete screw up from the get go.
Inexperienced divers wearing too much lead with no real dive plan, not hooking up their BCs to air and everyone drinking who was supposed to be watching them to name just a small number of things they did wrong.
The split fin thing is a complete red herring and the ONLY reference to it in the report was this on page 19 of a 26 page report.

Several pieces of equipment for the dive were non-standard, missing or not functioning properly:

o Both divers wore buoyancy compensator devices not attached to an air supply;​

o LT Hill was outfitted with two secondary regulators, one with an air supply and the other without an air supply;

o Both divers wore a single steel-100 tank with standard breathing air. Diving
under the ice or in cold water (water temperature below 37 degrees
Fahrenheit) must be conducted with a "redundant SCUBA system" which is
defined as twin tanks, per the Navy Diving Manual. The seawater temperature
for this dive was 29 degrees Fahrenheit.
o Both divers wore split fins designed for high speed, but which provide
minimal thrust in heavy diving. Split fins are not considered appropriate for
heavy diving, but rather for light diving and snorkeling.
o The divers wore their dive mask straps under their drysuit hoods, not
considered a safe practice in cold water.
o BM2 Duque's AGA regulator was missing a protective guard.​

This is just a small sample of what they did wrong. Read the report. Throwing in an opinion about split fins, unsupported by any data is really a shame because there is so much more to take away from this incident.​

 

[Gene_Hobbs]

there is so much more to take away from this incident.

I agree, there is MUCH more to look at from this incident. This was a single latent error, as supported by the Pendergast research, but this incident is a great example of how a series of latent errors can lead to an adverse event. I am happy to see people looking at the individual latent errors in more detail but let's not let these discussions turn out to be a fixation error in and of themselves.

 

[chickdiver]

Do you think they're crap, Chick? I have my doubts too, since I was the only diver left behind when turning around a pinnacle into current on Dominica once. After discussing this with other divers, and ScubaPro, I realized I was using the improper strong, deep, single paddle fin kick, which is what I was used too, and not the proper, rapid, shallow fin kicks required of splits. I'm still not convinced though that I'm safe with split fins in ALL conditions. I can tell you, they are great with mild to no current and require little leg action, but that might be true of all fins under those conditions?

Yes, I do (and have, since they first appeared 10 or so years ago). We used to teach people how to properly kick (ie what you discovered is the "wrong" way with split fins), then the industry started making fins that "sort of" work with the improper bicycle type kick most divers use because no one bothered to teach them any better. If you really want to be efficient in any conditions, learn a proper frog kick with a stiff bladed fin (ie jet fins)- there's a reason that's what cave divers use.

 

[Walter]

NOAA Nixes Split Fins : The National Oceanic and Atmospheric Administration's Diving Safety Board has just issued a report about the USCG incident last August when two Coast Guard divers perished during an ice dive near Barrow, Alaska. Part of the report: prohibits the use of split fins.

This is misleading. Split fins have been prohibited on NOAA dives only when "heavy loads or high currents may be encountered or when wearing a drysuit."

The split fin thing is a complete red herring and the ONLY reference to it in the report was this on page 19 of a 26 page report

That's true, but a tad misleading. Page 19 is the complete section on: FINAL ACTION ON THE ADMINISTRATIVE INVESTIGATION INTO THE DIVING MISHAP AND RESULTING DEATHS......

Do you think they're crap, Chick?

She was pretty clear. Having used a couple different types, I have to agree with her on this, they are crap.