The Surfboard Design Process

I began designing surfboards, (drawing pictures of them) sixty years ago. I shaped my first surfboard, a year later. One of the most useful tools I had, is little used (if at all) today. That tool, was invaluable to me, in understanding various shapes, and designs. It was especially useful when designing, and evaluating fins. What was that tool, you ask? (drum roll…) The slide rule. Long ago replaced by the hand held calculator. The slide rule was invaluable in helping me grasp the importance of understanding ratio/proportion aspects of surfboard design, and foil. Don’t fall into the trap of specific measurements, as it will change as other measurements change, like board length. Same thing for surface area (of the surfboard) to weight ratio. That relationship will tell you volumes about the kind of performance to expect from a given board design. One of my early mentors, design wise, was an aeronautical engineer, that was a regular at WindanSea, in the mid/late 1950’s. My point? Really give some thought to what you are trying to accomplish. Think it through. Draw some pictures, if you need to.

Thanks for posting this Bill, the surfboard design aspect fascinates and intrigues me, but seems like its not often discussed openly. I think half the guys here just want to copy an existing board, and the ones who do design work feel its like giving away classified intel to discuss the design process. And of course, everything you say regarding design will be challenged by someone with a diametrically opposite opinion. As a backyarder, there is more I don’t know than what I do know, but I enjoy designing my boards before I shape them as much as I enjoy shaping, and riding them.

For a second I thought you might be referring to something really high tech… like a pencil!

“For a second I thought you might be referring to something really high tech… like a pencil!”

That and a framing square.

The old master builders could figure rafter lengths, angles, including the bevel angles for the backing of hips and valleys to plane in with the roof slope, irregular hips and valleys (the intersection of two different slope angles), polygons, arches, ellipses, all with the framing square and the math tables stamped on the side. Truly amazing the stuff they could do! But I am unaware of its use in surfboard design!

I use one in the design/layout phase, on rolled out 30 inch wide, brown paper. On a blank, a snap line, and a framing square, are all you need. I also use a clear plastic shaping square. Total comfort with either one. Not rocket science, but you do need to pay attention to what you are doing.