Design Theory

To kick off the design process a basic understanding of the underlying design constraints and theories was required. I started developing this back in 2003/4, where I initially focused on fin design and flow across the fin surface with the hope of understanding how a fin should be foiled. One nice piece of work that dives into a comparison of the fluid flow about a single fin with that of a three fin thruster setup can be found here: CFD_report. I had just started to understand the relevance of Naca numbers and how the developed profiles can be applied to the fin design of a surfboard when I stumbled across SWAYLOCKS, the definitive surfboard design forum: www.swaylocks.com/forum. After many hours of interesting reading two pdf files were obtained that really help explain the basic design aspects of a surfboard.

• Surfboard_Design_and_Construction_1977.pdf
• SurfboardDesign.pdf

In addition to these two documents you may like to have a look at a brief but descriptive section on the Surf Line site. This section entitled: "A Surfboard Anatomy" is aimed at explaining the anatomy of different forms of the surfboard: www.surfline.com/mag/features/anatomy. Another site for Design ideas is: http://scsurfers.com/boardpage.html, but you just cant beat Sway's: Surfboard design theory

Before any of the above is put into practice you should also try to understand a little more about a surfboards application by considering the fluid dynamics that are employed when riding a wave. I wish that I had paid more attention in my Heat Transfer and Gas Dynamics lectures as it would definitely have made this area a little less baffling. Also have a read through Sway's as like most topics, there is some interesting information there. One thesis that I would love to get a complete copy of is "Hydrodynamics of Surfboards" by Michael Paine.

• Terry Hendricks, Ph.D. (sdbchguy) on Surfboard Hydrodynamics

History although a topic on its own, is one very important information gathering device that further helps you to gain a greater understanding of where the surf board came from to what it has become today. I urge you to have a read, there are a lot of sites around the net but keep in mind that not all the literiture documented is entirerly true. One popular misconseption that I have seen documented is that of who was the originator of the first 3 fin triangular configured surfboard. Simon Anderson is often acredited with this for show caseing his design in 1980 known as the "Thruster" setup. It is interesting to note that Malcolm and Duncan Campbell first built a 3 fined "bonzer" in December 1970 that also utilised single to double concave. Duncan states: "In 1970 there were three groups of designer/shapers who were working on the three-fin idea: Bob McTavish in Australia, Dick Brewer, Reno Abellira and others in Hawai'i; and my brother and I. But there were two differences between their designs and ours. We were the first to put the two side fins in front of the center fin. All the other three-fin systems prior to ours had the side fins either parallel to the center fin or behind it. Ours is the same fin position that you see today on all Thrusters — the dominant design on contemporary surfboards. In this sense, our Bonzer had the archetypal three-fin system. Just to get started here is a link to get some ideas: http://www.surfpedia.com/history/boarddesign.html

Along the way I also came across a good "free" piece of surfboard design software entitled APS3000 (now aku) that is downloadable at: http://www.aps3000.com/; Although after a bit of a play I have decided that both AutoCAD and/or Solid Edge (amongst other software) can complete the design activities for a HWS better. APS3000 looks great and is relatively user friendly; if you were planning to make a board out of a solid piece of material such as wood, EPS, PU, etc. this program would undoubtedly be a very useful tool.

Another neat site that I found quite interesting is entitled Surf Board Interactive, where you can play about with board shapes online.

Useful Links:

• sticktheory.com - Virtually a data base on surfboard technologies
• Surfpedia - History
• Terry Hendricks, Ph.D. Surfboard Hydrodynamics
• Michael Paine, "Hydrodynamics of Surfboards"
• SCSurfers.com - Ideas and principles