Strange single fin

I saw a friend at the beach yesterday and he had a really wild looking fin in his longboard. He has been riding single fin longboards for more than a half century, and is usually pretty conservative, but the fin he had in his board was the strangest thing I’ve ever seen. I didn’t talk to him much about it because I had just gotten to the beach and he was leaving. The surf was solid overhead maybe 3 to 4 feet overhead on the sets, so it must work OK. He said he liked it.

It looked like this with long wings coming off the middle of the fin but it wasn’t this fin. I searched all over the internet and this was all I could find.

Like this?


No the wings coming off the fin were long and I think slightly curved and not set horizontal. I’ll have to look again when I see him next time.

There are a lot of guys foiling now and he may have gotten it from one of the foilers. It must work because he used it on a day when the waves were really good.

I’ve seen one guy with relatively large horizontal wings on about a 7.5 inch deep standard looking fin,  about midway up the fin.  Seen the board/ fin twice while he was  in route to the water, months apart,  and left him alone despite my curiosity.

If he caught a wave that I saw, I did not know it was he. or notice anything special about the way the board performed. But they were better than average conditions.


Im not saying it does not work, or feel good underfoot.

Feeling good underfoot is all that really matters.


I’d try one despite my misgivings about the need for vertical lift/ stability  added to The tail.  Seems the wings would really need to click with the board’s rocker,  to a much higher degree than the small winglets on a wavegrinder WG2 fin.  When the wg2 clicks with board and wave. It is a pretty amazing feel. When they don’t it is irritating and sour, and one can form both  opinions on the same wave.

If I get a photo, I’ll post it. It was very unusual, so it’s probably a one of a kind.


About 1977 I made a fin similar to this one post by Unclegrumpy, I’d seen a fin by Reno Abellira, which had an adjustable AOA horizontal section and thought I should copy it.

The only and main problem with my fin and fins like this is that the lift is centred over the fin. I found that the faster the board went, the greater I needed to lean back to balance the focussed lift at the tail.

 I can see the logic that lift would lessen the drag but it only lifts at the tail, which is why Surffoils are 2 feet long and 2 feet wide to create a lifting ‘platform’ area rather than just a focussed point.


The first time I ever saw a fin, with little ‘‘wings’’ on it, was at WindanSea (circa 1956 or 1957).      It was on several surfboards (Balsa) shaped by Alan Nelson.       A design  genius, IMO, and a superior craftsman.       Alan ALWAYS seemed to be ‘‘ahead of the pack’’ in everything that he did. 

Saw my friend out in the water today. He said a guy in Hawi on the Big Island made it.

thanks for th pic.

Looks there is a website with a few more pictures of the fin.


Looks like no roll pin and dual fin tabs/ plates screws, a method I much prefer to the roll pin, especially  when fitting a thickened fin base tightly into a worn/stretched fin box.