Desperately Need Help

I have a giant midterm presentation next week and I haven’t found what I am looking for anywhere. I have asked my mentors, friends, teachers, searched the archives; I have done everything I can think of. So now I am turning to everyone here. I am looking for specific mathematics involved in surfboard design. I know the logic of it and how a board will function, but I need the specifics. I need everything from buoyancy to rail angles to fin placement to velocity to drag and orbital forces. I need anything and everything there is. If there is anyone out there who can help me out with this it would be much appreciated. I don’t know if this will help but I am building a 7’ long 21" wide 2 3/4" thick funboard, rounded square tail, no bottom contours, round rails. Thanks

Good luck! We can’t even agree on the basic premisisisis! Ha! Taylor

i remember a post that was titled geomotry in surfboards not that long ago try that in the archives. it might be helpful. i know that some of the guys on here can probably help you.

Sorry, man, but there are NO engineering/scientific/design formulas or equations of the sort you’d find in ship design, aircraft design, automotive design, house design or for that matter landscaping design. It’s all ‘try it and see what happens’ . There has been more scientific or engineering analysis of baseball bats than there has of surfboards.

Put it another way - the shaper is getting $50 or less, per board. The industry is a bunch of guys with hand tools and crude CAD/CAM at best, neither the money nor the inclination is there to do the studies - hey, the stuff sells fine without it. Let alone developing the methodology for testing and experimenting. Ship design in the 1830s was more scientificly advanced, better engineered.

Nobody knows the real ‘why’ of anything . It’s all guesswork, no numbers. I only know of one guy who has actually measured the speed of a surfcraft on water with any precision.

If I were you, I might

  1. PANIC
  2. Make something up
  3. Crib some stuff from Naval Architecture/Marine Engineering such as Skene's Elements of Yacht Design and Lindsay Lord's book on planing hulls. What the hell, you'll still be way ahead of the industry.
  4. Go to your instructor and say 'Hey, Prof, a funny thing happened' and see if you can radically change the aim of your presentation. To the tune of "Some Proposed Methodology for Engineering Surf-craft" or something like that. Pad it out with lots of sales numbers, industry estimates, that sort of BS. Cos the math just ain't there.
Sorry about that


I recently asked Swaylockian’s to steer me to some good technical information about surfboard design history. I received a reply from Oneula on Jan 5. Try checking that post and see if the thesis on surfboard hydrodynamics is of any help to you. Search under “dissertation” if you can’t locate the post.

Good luck.

If Bob Simmons were still with us he could answer your question as you asked it. He DID the math.


Skene’s would be helpful for say, working out the numbers while a board is in displacement mode (paddling out), but if your midterm is only a week away, consider that Center of Gravity, wave shape/speed, position on said wave, board flex , bottom contour, outline etc. all play factors in a wildly varying dance of numbers. My mind hurts even thinking about it.


The main reason that quantifying surfboard design into a tangable equation in enginnering terms is so hard, and mainly relies on trial and error is that is dependant on the dymanic properties of the waves themselfs, and this is more in the realms of chaos therory than standard physics,

check out the back catalouge of surfer’s path articals on line as they often have lots of the scientific stuff in.

As no one really understands this stuff any way, why not anylise the info and come to your own hypothasis and conclusions.

If your really have no time are panicing, and have to wing it, make it real technical but a bit vauge at the same time, go for marks for effort and pray that it goes over your lecturers head. back up what you are saying with actual evidence, and techinical info.

“you can prove anything with facts” - Homer simmpson

I don’t know if you can change your subject, but I think woody is onto something. We, as a humans, usually try to avoid chaos but under certain conditions, when it takes form, it brings incredible beauty and pleasure. Think surfing or marriage! Now thats something to ponder.