The link below is to an interesting article on three finned boards prior to the Thruster.
I know Bill Thrailkill was dabbling in this at least as early as the earliest designs discussed here - and possibly before.
Here’s images from the article if you can’t be bothered clicking on the link and reading the full story.
thnx 4 the link!
I did my first three fin surfboard, in the configuration now called a Thruster, in Aug/Sept 1964. It was three small ‘‘reverse’’ fins, each 40% of ‘‘normal’’ surface area, for a total area 120% of a normal fin of the period. Glass-on only. In the broad sense the ‘‘history’’ presented in the article, is a treasure trove of misinformation. I prototyped my removable PressLock fin system in Aug/Sept 1970, which was then available on the market in Feb 1971. That system was used by Dewey Weber, Hobie, Bing, G&S, Surfboards Hawaii, and Surf Systems. There were other smaller builders, but I don’t recall all their names. I suppose you could say that I dabbled in tri-fins, back in the day.
My brother was using the little plastic stick-on tri fins back in the early '70s. Probably about 1972. He’s posted a shot of him with the board he had them on here before. What we did wrong with this is we didn’t glue them on, we used a double stick tape. I didn’t think they weren’t solid enough make a difference.
Thanks Bill. I knew you could set things straight on this matter. When I said you dabbled it was “tongue in cheek”, as I know you were at the forefront at all of this.
Unfortunately “history is written by the victors” as they say. Or the “loudest” in other cases.
