Gentlemen, I am building a 8’0’‘, 19.25’', 2.85 single fin semi-gun. I think I’ve decided to go with a box fin setup for the fine tuning and versatility this allows. I’m looking for suggestions on fin template design and thoughts on the amount of flex, if any, that I should build into this fin. Also some feedback on the pro’s and cons of the fin box as well as the glass on option.
I am not a shaper, so my idea might not hold much water, but I like the Greenough flex fins. I have a nine inch on my 8,2 (fin box, of course) and it actually propels me out of turns. Well, it doesn’t really propel me out of turns, but it feels like it, because the flex fin helps you to maintain speed. Single fins sometimes easily lose speed in bottom turns, but not with the flex fins. That’s what they are all about…speed. Once you add side bites, or side fins, then that is beyond anything I understand. Some say they add thrust, but I don’t know. You are working on a semi-gun, so flex fins might not be the answer for you.
A board with the specks your building will not require a fin with very much tip or base area Unless you want to go with the old school fins like the ones that Gerry Lopez used on his Pipeline guns at about 8.0" or so. The board will be very directional and be able to work up and down the face of the wave but cutting back won’t be much of an option nor will a fin with a wide base and tip and a lot of dive be of much good unless you going to surf in very critical situations. The board will depend principally on its rail design and bottom configuration and rocker to perform well. It’ll need 8 feet of surf before it’ll be much good IMHO. I’d say a greenough Stage IV about 9.5" or 10.0" might suit the board well. A lot depends on your style. Hope you get the waves for this one. I have a couple of templates than might suit it pretty well so if your interested let me know. I’d definitly put a F/U fin box in it so you can fin the right spot for the fin and the right one for the conditions. Mahalo, Rich
Thanks for the detailed response Rich. I have been considering the greenough iv, but wasn’t sure. Under 8 feet I ride my own quad fin designs that allow me a lot of speed and focus on rail through turns. Thrusters have never worked for me. I Have been riding an 8’0’’ thruster, and 7’10’‘retro single fin through the last few winters in San Francisco. I love the flow and speed of the single fin, though as you said this one refuses to cut back due to the fin, as well as the pulled narrow tail design. I’ ve blended these two boards in the new design giving it a wider tail with more hip, more progressive rocker, and v through the tail. I am interested in those templates and your thoughts on how they might work on this type of board.
Hey Dan, From what you say you’ve make some positive changes in rocker and bottom configuration on the 8’0". I’ve surfed the kind of board you’re talking about some and understand what you’re getting at. I’m right down the road from you so it would be pretty easy for me to have a look at what you have and talk templates with you. Just shoot me an email at and we’ll go from there. We can talk templates in cyberspace or maybe meet down here in Santa Cruz sometime and hopefully come up with the next best thing or two for you to try. Mahalo, Rich
Greenough stage 4, 9" .
Hi Daniel, I’m working on something similar, 8 foot fungun for headhigh and up conditions, a bit wider tho at 20". I’m hoping you’d be willing to share some numbers and experince with similar boards. In particular I’m worried about rocker and rail shape. regards, Håvard