Just after the turn of the decade 1980 things changed in surfboards. It came with the fin. Actually 3 of them, on one surfboard.
It started in '81 and it seemed like within a year that was pretty much all you saw was the Thruster, also known as a tri fin. I personally didn't make the switch until the end of '82. I was a Greenough guy and surfed a single fin hull until finally deciding to try the Tri.
Not sure where that first tri fin I made myself went. I don't really remember how long I surfed it before making another one. But, I do remember that board well... and the one hang up I had with it.... fin location.
Never being one to take a ruler to another guys surfboard design... probably a pride thing... and even though I knew how important fin placement was I set out to figuring that tri fin thing on my own. The guys got to be different, or is it stubborn?
A few weeks ago I stumbled across some notes I'd written from January 1 1983 through January 18th. The notes were about 9 go outs riding my first ever tri fin. Even though I didn't remember writing about that board I always had remembered the problem I had with where the front fins were placed. So no surprise that in 2 of the 9 entries I mention a performance issue and the comment.. "I'm sure the fins need to be wider apart".
I fixed the issue by making another board. In retrospect maybe it would have been better to have sanded the fins off the board and re-positioning them. Guess making another board seemed easier.
Yeah, the tri fin design was pre fin system, so all those fins were glassed on. Funny too, there was the thought that if 3 fins are good maybe 4 or 5 fins would be better. I remember seeing a guy walk down the beach one day with a 6 finned board... I can't imagine glassing 6 fins on a board. Actually what's worse... having to sand a board with six fins on it. And the sander says " you want me to sand that? .. I quit.. sand it yourself".
Multi finned boards are great, and the removable fin system make them greater.