Here are a couple of interesting links about the Aqueon I dug up. There is a video link in the first one, but I couln't get it to work correctly. Perhaps a more familiar RealPlayer user can look at it and let us know if it's worth messing with. The second is a narrative of the '96 World Sub International. These are the folks that build man-powered subs FYI. At the end it appears that the inventor Calvin (supposedly 80 at the time) jumped in and demo'd the Aqueon.
Aqueon in action!
World Sub International - 1996
Towards the end the author says that Calvin originally marketed the Aqueon to scuba users but didn't have any success in that market. I can see why - the limited manueverability of this item makes it difficult to use up close and personal to the bottom. The same reasons that monofins really haven't caught on for the scuba users. Not to mention the movements are difficult when strapped to a 100 cubic liter tank. :t And I don't even want to think about trying to explain this contraption to the security folks in the airport.
I think one of the biggest advantages that this invention has is the ability to vary the angle of attack on the main fin. All of the aquatic mammals have this capability via a joint at the base of their fins. This allows a much more efficient swim stroke as the change in the angle of attack decreases drag through the water as well as forcing more water backwards rather than up or down. Look at any video of mamals in the water from a side view and you can see this appearant this adaptation is.
Mammals in action!! Belugacam!
I think this is also what enables the reduction in fin size/shape to something more hydronamically feasable. If you look at the ratio of body size to fin size you see that the human with a mono is WAY out of whack when compared to other aquatics. I believe that the way we have compensated for the inefficiency in not being able to modulate the angle of attack is by upping the size of the fin surface. And while we are pushing more water backwards (more speed) we are also pushing a lot more up and down (wasted energy) and creating a lot of drag (fin is WAY too big). If you go outside the aquatic mammals and look at tuna or shark fins, you see that big fins are not required to produce large amounts of speed or power efficiently.
The variable angle of attack is what I think the next great revolution in monofin design will hinge on. A couple of things to note. Calvin has recaptured some of the wasted energy of the stroke through the efficient use of a spring. While I think this is a good engineering fix (you can tighten and loosen the spring for different users strength) I don't think that this would ever be allowed in AIDA competition for the same reason a pedal powered propeller would be disqualified. Too much mechanical aid to the human. I am not sure that I entirely disagree......part of what makes freediving so addictive is the feeling of freedom and naturality it seems to impart. Semantics? Maybe.......I know I freedive with long fins and goggles.......but there is some indefinable "unnatural" line you cross when you put my bicycle in the water and I ride it around. :t Secondly, if AIDA can't unanimously endorse Liquid Goggles (a product that is so awesome, easy, and FUN to use that it is mind boggling that EVERYONE doesn't have a set just to play or set records with because you don't have to equalize your mask) then there is no way in H - E - double hockeysticks that they are gonna approve of this.
I know that we try to recoup some of the lost energy of the monofin stroke through materials that rebound - like fiberglass. I think that if someone could make a springy fin that attatched to your shins (similar to the way the Aqueon attatches) and allowed the fin to change it's angle of attack throughout the finstroke with something like a hinge you would see some new records being set. If you could use strips of fiberglass along the hinge to recapture some of the stroke energy it would be even better. And as long as you didn't change the overall profile of the fin it may just be possible to get it approved - although of the entire process, this is imho the sketchiest part of the plan. I don't think that placing the fin in the middle of the body would be accepted. As Eric F can attest, most people are not open to change, even when it makes the most sense in the world to do so.
Sorry for rambling......this topic is somewhat of a passion of mine.
Oh and if you look at nothing else in this post, check out the beluga cam. I have it in a little frame on my desktop just so I can watch the belugas and destress while working.
