Fin-tastic!Kevin Gurr for Dive Magazine
On Excellerating Force Fins
THE FIRST word that springs to mind when you see a pair of Force Fins is 'gimmick': some American manufacturer trying to get a marketing edge by being different.
I remember first coming across Force Fins advertised in the now-defunct Aquacorps magazine in the early Nineties. I didn't pay much attention until a couple of years ago, when I was working on a project with leading technical diver Billy Deans and one day he jumped in the water with a pair on. Having been around diving a long time, Deans is someone you listen to, so I inquired if he was trying out a freebie. His was response was to hand me a pair without saying a word.
On slipping them on my feet, my first reaction was that I wasn't actually wearing any fins, they seemed so light. Being trained in the old school, I started diving with a pair of fins that resembled two planks of wood. Surely these new-fangled things would just disintegrate when I hit the water? But first I had to get to the water. Force Fins have these little bumps on the base so that, without adjusting your center of gravity, you slide across the deck - not too gracefully with a twin set on! Eventually, I mastered the technique and entered the water.
To begin with, I didn't notice any difference, but then I power kicked off and it was like catching a ride on a passing shark: little effort and lots of speed. Even after a long swim, the usual first twinges of cramp weren't evident. I was sold.
So, how do they work? Well, with all fins, propulsion power is generated on the down stroke; the up stroke is almost a waste of effort and is tiring to the muscles. The little bumps on the base of the Force Fin, however, act like the bumps on a whales back, creating small vortices that break up water's surface tension and allow for an easier up stroke. The down-stroke power is increased by the adjustable plastic ' whiskers' on either side of the blade. Normally, water flows over a flat blade; with the Force Fin, it's channeled between the whiskers. The more turned in the whiskers are, the more the water is channeled and the more power is produced.
The choice of fin material also helps to increase the power to effort ratio. The force fin is almost rigid, so that, when it does not bend against the water, it naturally springs back ready for the next kick. Another plus is that your toes aren't jammed into a blister-inducing pocket. The open-toe design makes for a much more comfortable ride. In addition, the strap is a webbing band that won't rot or break and is easily adjustable. At last, no more carrying spare fin straps.
I've used Force Fins on and off for two years now and I think they're excellent. I've never had any entanglement problems with the whiskers and they definitely cause less stress on long swims. They're a little smaller than most fins, which can be disconcerting, but stick with it- they're worth it!
Force Fins come in a range of styles. The ones shown are Excellerating Force Fins, which cost £194.20. For more information, contact UWI Circle on 01420544422.