From Greg Webbers website at. http://www.webber.net.au/ The Vent Fin By allowing water to pass through the fin, the vents reduce the resistance felt during turns. The affect of this design feature is most noticeable when the fin is being forced sideways through the water, since less resistance is felt than is normally the case. However, the vents do not seem to reduce the stabilising function of the fin when its passage through the water is at an angle approaching its own alignment. Concept and design by John Webber. My First Surf Spookies was ledging at six feet, green barrels were piping off with every third wave unridden. Only a few guys out so it was one of those surfs that you could pick and choose. It was my first surf on the Vent Fin. I was excited and at the same time a bit nervous that if it (the fin) didn’t work, I’d really eat it. Spookies can really slam you if you blow it. It was also my first surf in a month. A combination of aging body, stiff joints etc. and an ever recovering back injury had meant that good surfs were less frequent. To put it bluntly, it was giving me the shits going for a surf and having to nurse turns. My first wave had a long wall with a hint of a backdoor tube looming from the takeoff. A couple of seconds in the barrel and out onto the shoulder. So far so good, in fact I hadn’t even thought of the fin, which was good because at least it wasn’t doing anything wrong. Now for a cutback. No worries, in fact that was the first turn that I really noticed the fin, it was much smoother going from inside to outside rail. Then for the bounce off the whitewater. This has always been a problem of timing for me, but to my amazement I found myself facing the whitewash in a position more like you’d be in for a backhand closeout reo, so I hit it dead on without a wobble. Yay! It happened with so much ease I couldn’t believe it. Too often, that’s where I’d come unstuck, or put more accurately, that’s where I’d get stuck, and then blow it. This fin was definitely doing something good, so I was amped. OK, so that was only wave, I thought, but it seemed to help all sorts of turns, not one kook out for the whole surf. As it turned out, it was the best I’d surfed in five years. I rang my brother Greg. I was frothing at the mouth, telling him about the surf I’d just had. He was excited and keen to try the fin. The next day, brother Will surfed it at the point and loved it. Greg tried it the following week and was surprised that there was not one down side to the performance of the fin, with all the freeing up of the tail fin, there was no loss of drive or lack of stability. It performed well in small surf, but might also free up stiffer, bigger wave boards we thought. Long boards might benefit as well. It’s early days, with less than a dozen having been foiled by Greg and myself, yet already Kieren Perrow has used one at Jeffries bay in a few heats and even Mark Richards is testing one out. Greg has showed it to FCS and with a bit more refining it might find its place in their range, we’re hoping.
Are the size and shape of the holes significant? If so, is there a mathematical ratio or anything to govern their size and shape?
my expectation is that this gimmick won’t go anywhere except with the guys who buy fins with “tunnel” holes in them. Has anyone read the very nicely written information about flow posted a few days ago? www.av8n.com/how/htm/airfoils.htm and you’ll see that these holes so completely destroy smoot flow that, well, read the somewhat long explanation. Really, you’re just using a fin with smaller surface area and which creates a lot more turbulence. Why not just use a smaller or narrower fin? Read the airfoil info and you’ll know where most of a wing’s lift is generated. Then you’ll know to avoid flashy gimmicks like this. If you can’t understand at least 80 percent of the airfoil reference, buy lots of these fins. Put one on the roof of you car, another several on your boards, one on your nose, another in your pants. Geez I’m grouchy today
Not saying this a copied design but I’m all but certain that someone was selling molded fins like this some time ago. Can’t remember the name of the company. Can anyone help me on this?
Randy Laine made some back in the 70s/80s. His brother Wes surfed them for a while. Others have made similar fins. Greg Webber’s curved fins are much more interesting and it’s too bad more (less expensive, different system) curved fins aren’t on the market. Rob Olliges