the question was asked. I was there when gene took a pencil and "free" drew our fin template on some flimsy template making board. we messed with the height a bit. gene had the front curve and the back curve in his head. to me it looks like the profile of a "pigskin" stuck in the sand (for those american "football" enthusiast). truth be told... gene has seen a fair share of bing surfboards in his time. all of the photos below are from the classic bing surfboard site (except for the top one). that site rules.
"So here's the story on the fin. I walked into the Garden Grove factory one morning at about 4am to work on bb#1 and looked up and saw this POS board that Michlers dad found in a trash can back in the 60's. No logo, no idea who made it but I liked the fin shape and how the trailing edge was cut in so the fin could hang off the tail. Got a ladder to get up there and traced it on hardboard, cut it out, then whittled on it for a while. Turned out kind of what I scribbled out for GG a few days earlier. So I had a this fin template before I finished my coffee. If I knew it was going to lead to this much discussion I would have spent more time on it."