Yes, they are. From that point on, out to the rail, the tracking gets stronger and stronger. The solution is move the fins closer together, or as the fins approach the rail, they should get smaller and smaller. In his blog, he gives the impression that this is original thought, by him. Next thing you know someone will win a contest with the setup. Then it will be the new flavor of the day.
SHAPER SINCE 1958
Well. it's only taken me 3 years to get back to looking at a Thrailkill "two in one" fin again, but I've made a start.
Here's the first half laminated up.
What? Is that legal?
All the best
Personally I'm always ready to learn, although I do not always like being taught. - Winston Churchill
Quite impressive. Very well executed.
Ha, I love the photo of Bill routing out the boxes with no mask on.
Silicosis is pretty fashionable these days I guess.
Still going slowly. Both halves laminated and sanded. Now for the gloss coats, final sanding and eventual joining.
You might consider a ''rattle can'' clear matte finish, as your final coat. The way you've engineered the single base design, is quite clean, simple, and creative. Ride report, asap, please. As said before, well done!
Surfed it today in 4' beach breaks. Surfs like a single fin but with a lot of extra "sqirt" and hold. Definitely something worth exploring if you are a fan of single fins. It didn't feel like it had a lot of extra drag (unlike my previous design), but stomping hard on the tail I could feel the horizontal elements at work.
Excuse the wide angle lens effect on the attached images. There is no fin cant or toe in on the design.