Force Fin ---> Seal Fin Concept

[SeaRat]

Ty,

I could easily make the regulator comply. The hose on my primary regulator is 8 feet long. The back-up second stage can easily accommodate a bungee, and I could easily put a bolt snap on my primary. But, I won’t be buying a backplate, harness and buoyancy wing anytime soon.

The Seal Fins probably will work with a helicopter turn, but I’ll have to try that in open water next time out. I’ll also try the back-up kick. Looking at the demo, it appears that the regular fins are also not made for a backup kick either (actually, there is no fin made for a backup right now, in my opinion). I know Bob’s theory about relief on the upstroke being a way of minimizing cramps. But, I simply disagree. To me, the upstroke is also needed to balance out the downstroke on the other leg. The foot pocket is the best means of minimizing cramps, and the Force Fin has one of the best in the business. But loss of the upstroke handicaps this design; the Seal Fins rectify that loss.

I have been diving 63 years now, and have worked to define best practices in diving. I have a BCD patent to my name too (that’s the Para-Sea BCD I’m wearing in the photo above). While no manufacturer has adopted the ideas I have put together, that does not mean they are invalid. It means that companies look to make money, without regard to some of the safety aspects of their products. The requirement of a heavy backplate, back bladders, and the requirements on certain regulators, for instance, are driven mostly by trying to make money rather than best diving practices. I dove a back-BCD which was built into my wetsuit for a number of years, but also had a CO2 vest on when doing it. The reason? I wanted a front-mount inflation system for surface safety. I also have no need to use a helicopter turn, as I can easily reverse my course of travel in other ways. In current, I will usually do a 3/4 flip turn to reverse in the river. Sometimes, I’m already swimming down on my back towards the bottom, and use the current to help make the turn (try that with a helicopter turn). These kinds of requirements are a turn-off to me.

John in Clear Lake with Bill Herder's BC by John Ratliff, on Flickr
This shows me diving Bill Herter’s back-mounted BCD built into one of his custom wetsuits. It’s the white area of the wetsuit.

IQ-6 Buoyancy diagrams by John Ratliff, on Flickr
Here’s an example of one of my discussion points from a paper for NAUI’s IQ 6 in the mid-1970s.

Last year, I was told by the lifeguards at High Rocks that a Clackamas County Dive Team was in the water. I dove, and.with my swimming techniques passed them going downstream. They were concentrating on their frog kicks so hard I don’t think they even saw me. So my impression of these techniques is not that great.

John

[Aquala1]

Alright then. Best of luck on your Seal Fin concept, and keep us posted on your progress.

[scubalawyer]

I find the whole concept of diving philosophies intriguing. I have never taken a GUE class, and although I am self-admittedly "set in my ways," I know I would learn something were I to take GUE fundamentals class. Concept is one thing, actually doing it another. When I became full cave certified 22 years ago my friends and I entered the class as long-time NAUI Instructors confident there was not much else we could be taught as divers. We were wrong. We trained under the "Hogarthian" equipment system and learned a lot about bouyancy and finning techniques and black-water diving and body positioning awareness that we had never been exposed to. Our cave Instructor commented that our experience level made us more comfortable in the water than many of his students, and that accelerated our training immensely (our graduation dive was a 3.5 hour double stage dive rather than a normal dive with back-gas alone) but we couldn't have done what we did without learning and re-learning the basics and practicing them. I still use basic techniques learned in that class even on solo DH pure vintage dives in open water. I plan on going back to take a side-mount cave class not only as a refresher of basic dive techniques but to be able to fit through restrictions that back-mounted 80's prevent. There is one off-shoot passage with a tiny but passable major restriction in one of my favorite Mexican cave systems that I keep eyeballing to explore as I think it hooks up with another cenote about a 1/2 mile away. But, I digress. Point is I never stop learning and even if I don't agree with any particular diving philosophy, I'm sure I would take some kernel of information away from it that would make me a better diver. My 2psi, feel free to ignore me.

Here is a video I took on a single stage dive in 2004 showing some finning techniques:

[SeaRat]

Guys, it’s not that I’m not going to learn more, and keep learning. But I am at an age, 76 going on 77, where I am much more cautiousabout what I do, and my wife is also very cognoscente of all my activities. I doubt she would like for me to dive caves, or for that matter learn cave diving. These techniques are fine for what they were developed for, the cave environment. I am intrigued by underwater swimming techniques, and my whole emphasis is on making our movement through water more efficient, and to a degree faster.

One of my childhood b“hero’s” from the underwater world is Frederick Dumas.



If you watch him dive through wrecks, you don’t see the precautions that today’s divers take. You see someone fred swimming through these wrecks.

So with my age, I’m diving solo, but with a float so everyone on the surface knows where I am. That’s the one compromise I have, but with it comes the potential for entanglement with the float’s line. I’m simply happy to be in the water, and still diving.

IMG_3386 by John Ratliff, on Flickr

Yes, I could learn from side-mount diving, though I think it would inhibit some of the techniques I’ve developed for using the dolphin kick. But there is only so much time, and I really want to spend that in the water, trying to understand the biology and ecology of the river and estuarine systems I actually dive in. I also enjoy photography, and have developed some really nice techniques for getting good photos. Early on, I developed techniques for buoyancy compensation when even the concept of a BCD was just being developed. I worked with Bill Herter of Deep Sea Bill’s to pass his knowledge of “push button diving” on to the next generation through the NAUI International Conferences on Underwater Education (IQ6 and IQ7 in the mid-1970s).


Subtidal Clambed Survey007 by John Ratliff, on Flickr
This is about the most streamlined back-mounted BCD ever devised, Bill Herter’s back-mounted buoyancy made of two sandwiched layers of 1/8 inch skin one side neoprene built into the back of my wetsuit.

John Demonstrates Back-mounted BC copy by John Ratliff, on Flickr
Here I’m demonstrating different concepts of buoyancy control to attendees at IQ6, and I believe if you’ll look, you’ll see some representatives of Scubapro here. It was not much later that Scubapro came out with their wrap-around BCD, and Bill Herter always felt that they took that concept from his initial neoprene vest that I demonstrated there.

Now, with the Force Fin, I’ve developed the Seal Fin, which through these writings I hope to pass on to a new generation of divers. I sometimes go against the grain of the current diving methodologies, which can cause some people some pain. But that is how we grow, by experimenting. I use my dive site at High Rocks as it has everything Ineed to evaluate safely some equipment, and to learn about the aquatic system. I’ve documented lampreys spawning in currents that people with only a frog kick under their belt of experience could not even negotiate. I’ve re-conditioned the Fara-Fin so that it actually works, and found that after altering the angle of attack, it is one of the most powerful fins ever developed.

Fara-Fin Mod-2 by John Ratliff, on Flickr
Two pairs of Fara-Fins, with the foreground pair (with stitches) having the altered angle and the rear pair being unaltered and almost unusable.

So it’s not that I cannot do a GUI course, but that I’m already committed to doing a bunch of other things, and that simply is not on my list of things I would want to accomplish.

Seal Fins at High Rocks by John Ratliff, on Flickr

John

[SeaRat]

Okay, I now have two more dives on the Seal Fins. Both are in the Tualatin River, at Cook Park. Neither was a particularly hard dive, but both were over the bottom that is easily stirred up, so I used the frog kick more than I usually do in the Clackamas River. On the last dive, I did practice a few maneuvers, including the helicopter turn and trying to swim backwards. Well, the helicopter turn was no problem, but swimming backwards with that fin configuration just didn’t seem to work.

I like the Seal Fin concept mentioned above, and have been using these fins throughout my dives this summer and fall. But that’s not many dives (I’m getting older, and if my body doesn’t feel like diving, or if the traffic is too bad, I simply don’t dive). I did find out that with the two blades on my feet, I had enough upward thrust to counteract the buoyancy and twist of my Ikelite Housind with my Canon F-1N inside. I was taking macro photos, and the upward thrust was necessary to ensure good closeup/macro photos of the mussels and crawdads.

John

[banana]

ForceFins are interesting. I have been using the Originals and the Pros for about five years. I dive warm water reefs and avoid swimming against the current whenever possible.
The FFs that I use have give little or no propulsion on the up stroke. On the down stroke they give considerable and efficient thrust. For snorkeling on the surface they are pretty useless.
When people say their FFs deliver equal power with less work I think they are referring to the effortless but useless up stroke with its built in rest cycle combined with the efficient bucket of water expelled in the down stroke. For me there's nothing like them for gliding effortlessly over a reef. They have a reputation for being worthless for frog kick, but I have had good luck with a faster light flutter in keeping up with divers in swim throughs without making a mess.
I find SeaRat's experiments with the FFs very interesting. What I believe he's doing is trying to make the up kick a useful part of the kicking cycle.