do split fins really help reduce air consumption?

[MikeFerrara]

OK ralph. Lets call my position unsupprted. My point is...Even if we collected data and proved that at a constant speed and direction that a flutter with splits was more air efficient, that still would not describe how most diving is done. We go this way and that, stop to look, turn to look and sometimes find ourselves near the bottom. When performing all these manuvers I don't think your kick or the psplit fins will cut it. I was originally taught to flutter. my second pair of fins were splits. I was never truely in control in the water until I learned other techniques and got different fins. A couple weeks ago I spent some time in the pool using split fins trying to figure out how to help a student who was using them. I could not effectively do the kicks and control I was trying to teach with them. I guess to develop an effective argument I could waist valuable time getting numbers for you but it would not make the kick or the fins any mroe versital. As far as standard teaching practices, thats what I balme for the totally blown out vis we had by 10 AM on sat and the fact that by 4 pm on sunday after all the rec divers went home the vis got nice again. I watch hundreds every weekend fight for direction control and destroy the bottom from more than 5 ft above it.

I guess I have not done a study that tests the one variable (futter). However if the advice I gave in my original post is taken it will do more to improve air consumption than buying split fins, even if I should have worded it differently.

I'm not trying to pass myself off as anything, but I do try to pass on what I have learned the hard way in order to help divers dive better. I see the trouble divers have. I see how they are taught. Having had to climb that learning curve, I try to shorten it for others.

I think I will design a test. It will include turns, vertical ascents and descents. The course will be along a line that must be fallowed exactly (no radious on turns or over shooting) We will gather data on time, accuracy, consumption. Silting will also be looked at. I will lay the course out over and around the cars, trucks, trees and bottom contour of gilboa quarry.

I'll give some thought as to the details and let you know. Would you care to participate?

 

[rcohn]

MikeFerrara once bubbled...
I think I will design a test. It will include turns, vertical ascents and descents. The course will be along a line that must be fallowed exactly (no radious on turns or over shooting) We will gather data on time, accuracy, consumption. Silting will also be looked at. I will lay the course out over and around the cars, trucks, trees and bottom contour of gilboa quarry.

I'll give some thought as to the details and let you know. Would you care to participate?

Thanks for the offer but I think I'll pass. This has virtually nothing to do with the way I dive, except for the very rare swim through. Most of my diving involves relatively straight swims over reefs or the outside of wrecks, wide radius turns are almost always possible. I have no reason to use a less efficient kick so I can swim over the reef pretending I'm a cave diver or penetrating the Andrea Doria.

Fine control is great, but when you're on a long straight swim through open water (no bottom in sight) keeping up with a DM who is covering as much ground as possible looking for sharks, it does you no good. Then you need to know and use whatever kick provides the best speed and air consumption. A frog kick will never even keep up the stiff pace. And by the way, this isn't hypothetical, it describes much of our diving in the Revillagigedo Islands.

Ralph

 

[MikeFerrara]

Well...I guess you know what works for you. I have never followed a DM (other than in my OW class). I don't need to keep up with anyone. We travel at a speed that is comfortable for everyone. But, I still think I use less air when frogging so I'll test it and get bback to you. I'll swim at a constant depth for a period of time (long enough to use enough gas as to have decent resolution). I will try to keep speed constant, but it won't be a race as max speed won't give max efficiency with anything. I'll compare a frog to a flutter but won't bother with the splits because there are too many important techniques that I find impossible to use with them.

 

[rcohn]

MikeFerrara once bubbled...
Well...I guess you know what works for you. I have never followed a DM (other than in my OW class). I don't need to keep up with anyone.

If you never follow a DM, you've never been to many exotic sites where some of the most exciting diving is found. In open water dives where buoys aren't used, the boats follow the diver's bubbles and the group stays together. Also good DMs know the sites and the spots to find the rare creatures, just try finding a seahorse or frogfish on your own. Some of my best dives have been spent following a DM.

MikeFerrara once bubbled...
But, I still think I use less air when frogging so I'll test it and get bback to you. I'll swim at a constant depth for a period of time (long enough to use enough gas as to have decent resolution). I will try to keep speed constant, but it won't be a race as max speed won't give max efficiency with anything. I'll compare a frog to a flutter but won't bother with the splits because there are too many important techniques that I find impossible to use with them.

I'm sure your tests will be completely unbiased so I look forward to hearing the results. You're off to an excellent start, excluding the fins that many divers find to be the most efficient for flutter kicking. Though it's probably just as well, split fins used with poor technique produce terrible results. And, by the way, not all split fins are the same. Using one pair and concluding all are bad would be like my trying Force Fins and then concluding all paddle fins must be useless too.

Just as a note, it won't surprise me if a diver who uses a frog kick exclusively finds it to be the most efficient. The real question is for a diver who is equally well trained in both a flutter and a frog kick, which provides better air consumption.

Ralph

 

[MikeFerrara]

I think I can do a flutter kick ok. All in all I would say I have more dives flutering than froging. I used it lamost exclusivly until I learned better. I am aware of how split fins are intended to be used and I can perform the kick. It is all the other kicks that they don't work well for. I have not tried all of split fins, only the original Apollo, the Genisis and the sherwood. That was enough. I am going to eliminate the split fins so as to limit variables. Besides if I compared a frog to a flutter using a split fin the test would be totally invalid due to the fact that every split fin I have tried is completly useless with a frog kick. So...to compare kicks I will use a fin that can do both so I can compare kicks not fins.

As far as wether or not I have been anyplace exotic, I guess that would depend on your definition. I have dove some fantastic wrecks in the great lakes and some incredible caves. Seems exotic to me. I didn't find any frogfish though. I have seen species of cave creyfish that only exist in one cave.

 

[rcohn]

MikeFerrara once bubbled...
I think I can do a flutter kick ok. All in all I would say I have more dives flutering than froging. I used it lamost exclusivly until I learned better.

It's not enough to have used it in the past, you need to be well conditioned to perform the kick in the present (at least by the time you do the testing.) Conditioning fades quickly on any technique that is not routinely used. I walk all year but I need to build up conditioning to ride my bicycle each summer, despite the fact that I ride on a trainer every week during the winter.

MikeFerrara once bubbled...
I am aware of how split fins are intended to be used and I can perform the kick. It is all the other kicks that they don't work well for. I have not tried all of split fins, only the original Apollo, the Genisis and the sherwood. That was enough. I am going to eliminate the split fins so as to limit variables.

Those are some of the worst choices in split fins in terms of paddle fin style control. Atomic Aquatics fins or Scuba Pro Twinspeed (not Twinjet) fins are much better choices. I suspect they may have less control than a set of Jet fins, but the are quite adequate for most open water divers.

MikeFerrara once bubbled...
Besides if I compared a frog to a flutter using a split fin the test would be totally invalid due to the fact that every split fin I have tried is completly useless with a frog kick. So...to compare kicks I will use a fin that can do both so I can compare kicks not fins.

However, you're freely giving advice to open water divers who will never see the inside of a cave. Are you concerned with how fins will work for them, or do you believe that everyone must dive the style and sites you do?

MikeFerrara once bubbled...
As far as wether or not I have been anyplace exotic, I guess that would depend on your definition. I have dove some fantastic wrecks in the great lakes and some incredible caves. Seems exotic to me. I didn't find any frogfish though. I have seen species of cave creyfish that only exist in one cave.

The sites sound quite exotic and challenging. I've never found any frogfish and certainly not a seahorse either, but I've been lucky to have good DMs that can point them out.

I've no idea what students are like in Indiana, but here in Massachusetts over 90% of the students I deal with plan to do some tropical diving. Most students plan to dive the tropics exclusively. Maybe your shop only trains future cave and wreck divers? However, if you're training students to do the standard recreational tropical diving, shouldn't you at least experience it a few times to understand the gear and techniques that will best serve their needs? Understand procedures used by DMs and different boats so you can instruct them on how to handle gear, enter, exit, and dive safely and efficiently? Choices on exposure protection, accessories, luggage, etc., items every shop in MA sells, are all influenced by the actual conditions. Don't your warm water students (assuming you teach them) deserve an instructor who's done the type of diving they aspire to?

Ralph

 

[MikeFerrara]

I obviously dive open water also. I have dived warm water off of commercial boats. I don't think I need to do it all over the world when thats not what I enjoy. The techniques I teach (and I do teach students to flutter as well as the other kicks) will serve them in a wide veriety of situations. I do not promote cave diving. I love it but I don't promote it. They will over time add to their knowlege but they won't need to through any away.

I don't think I am doing my students wrong by not spending my vacation in the tropics any more than another instructor is theirs by not being a cave diver. However since you mentioned it, I do think many instructors seem to teach assuming "tropics only" diving and fail to provide a good foundation that will serve the student no matter what they decide to do. I saw a quarry with hundreds of divers this weekend. Nearly all were head up, neg buoyant and finning like crazy all the time (including instructors). Their equipment configuration might work in the tropics where the heavy suites and lots of weight are not needed but it seems nobody taught these divers anything about balance and trim. Vis was gone by noon on Sat. By about 4 pm on sunday after most had left the vis was great again. It is not I who am failing my students. My students can leave the bottom or coral unharmed anywhere in the world.

According to the reports that I receive my students and the crews on the boats they dive on are very impressed with how prepared they are.

 

[rcohn]

I've dove with a few instructors over the years and I've never seen one dive anything remotely as you frequently describe. We have quite a few instructors on this board, maybe some are even checking out this thread and will help out. Hey, how many of you guys swim head up, negatively buoyant, constantly kicking up the bottom??? Walter? Submariner? Any volunteers out there?

I've seen newbies and a few old-time cold water divers swim in the manner you describe, particularly some of the lobster divers, e.g. my buddy a couple of weekends ago. I've never seen an instructor who couldn't control his or her buoyancy, produce a passable trim, and leave the bottom undisturbed.

Ralph

 

[MikeFerrara]

The best place I have found to see it is Gilboa quarry in Ohio. Not only is trim bad but they have dangling alternates and gages on their students.

I don't mind debating dive technique with you or anyone else but I don't think that's what you want to do. It is best that I now leave this thread. Of course, I would agree to a private discussion.

 

[rcohn]

Well it's been entertaining.

One last note, in case someone thinks I'm exaggerating how hard you may swim on dive trips, I just read this report on D2D tonight. http://www.scubadiving.com/members/tripreports.php?s=1633

Similar to Wolf, the plan here is to enter at the front of the Arch and head down to the outcropping of large boulders on a ledge that overlooks a drop-off of god knows how many feet. They call this perch the bus stop, because when the whale sharks are here, you can just sit and wait for the “busses” to drive by. Everyone in our group was just hoping to avoid a strikeout. All we had to do was see one whale shark and the trip would be made. Well, it took us about 3 minutes before Santiago spotted the first whale shark, although how he saw it I have no idea. The vis was only 40-50 feet and he wears glasses...but not underwater. The best thing to do was just watch Santiago. When he started kicking like there was no tomorrow, just follow suit until you see the same thing. For the first encounter, I was at the front of the pack with Santiago and we were really the only two in our group of eight to get up close to the whale shark since it was pretty far away. It was stunning, but I was thoroughly exhausted and I’m in pretty good shape and a youthful 32. How the old geezers in our group would keep up (those over the age of 33), I had no idea!

Do you think they were frog kicking?

Ralph