I posted a little of this some time ago: the tuna is one of the speediest fish because it has learned to use the swirls/eddies/vortices that come off it's undulating body by timing tail fin movements to work with the eddies rather than have the eddies simply cause drag. I believe the research was done at MIT and can dig it up tomorrow but the jist of the revelation is that tuna are not only fast down the line but are even more amazingly fast through turns. Starting to sound useful. Well to a tuna it's a matter of survival. They actually can initiate turns by pivoting around the eddies their bodies create. The claudal fin while very efficient is just half the story. Yellow fin is good raw with a little soyu. Rob Olliges
>>>Your words, "The man who developed and demonstrated the radical performance of the modern high aspect ratio fin is also a living, functional testimony for surfing without any fins!" Can you explain what you mean. This makes no sense to me at all. The sentences seems to be in complete contradiction of itself. His use of the inflatable surf mat for over 50 years. --- Rich, Among other things, George is credited with the development of deep, flexible high aspect ratio fins. He demonstrated/documented his ideas through some very powerful, fast and efficient surfing... both on the wave`s face, and inside the tube. George has also dedicated most of his 6+ decades of life on this earth to the advancement of mat surfing. In contrast to George`s kneeboards, advanced surf mats have no stabilizing fins. So, I`d say there`s a bit of an enigma in all this, but no real contradiction. The more we know, the less we know...
Rich Small little steps and advancements over time account for big changes. Refinements, no matter how small can make big changes. I m sure that you know the effect of changing fin position or adding a little V can make a board feel a hole lot different. Keep at it, most of us appriciate what you are doing.
I saw a photo somewhere of a "RoboFish" - a robot fish used by MIT or one of those places. They were trying to figure out how it was able to swim so fast. A google search or two might be able to access some information.
Here I go again.Same old stuff for the last 40 years.Why do all surfboard fins have to look like an appendage of a fish?Twenty five years ago I epoxied a small coke bottle on my board for a joke and it actually worked really well.Why don't these so called fin designers check into something other than "fins".Don't give me the "evolution..perfect form..deal" its a surfboard not a fish.
I can somewhat agree with what cleanlines said. A fish has a few things going for it in that it can pivot or flex its whole body into a turn and can adjust the angle of attack of its fins. On the other hand I have seen and tried many odd/funky looking shaped fins from rectangular shapes to boomerang shapes to the Cheyne Horan star fin to forward raked fins and didnt like any of them. The traditional shaped fins just felt better....whatever that means. http://www.pbs.org/wgbh/nova/xplanes/airborne.html#
Since a fish angles its fins to turn, could a surfboard fin be designed to pivot or change its angle in response to the water flow pressure exerted on it.
It`s the most fucked up idea ever: fin "innovators" making dead things from a copy of a living thing. Tuna fins, dolphin fins. They`re supposed to be active- not fiberglass and injection molded plastic. Such grossly misdirected energy. No wonder there`s hardly any real design progression in the "surf world": the monkeys are running the phuggin zoo! I`ll check back in another 10 years to see if anything "new" has happened yet.
The shape/rake of a marine animal's fin suits the surfer well because it can automatically shed debris like seaweed; boogie boarders; fishing line, etc. A dolphin's fin is mostly connective tissue which is both rigid and pliable. The pectoral fins play a major role in steering and can be altered with finger-like bones. The dorsal fin is mostly for stability. Dolphin propulsion comes mostly from a horizontal tail fluke. A lot of variables to play around with as we consider designing control systems for surfing. I think only a few of the possibilities the dolphin (just one marine animal) presents have been explored in surf vehicle designs. That's why we still look to animals. Fini, Rob Olliges
What advantages would there be to a fin that could optimize its angle of attack by moving? http://www.blakestah.com/surf/