Volume v's Surface area

some thoughts from bert burger;

Thickness, the Myth uncovered ..
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Bert Burger Feb 3 (1 day ago) to me, Sunova Sorry to say , its all about surface area . These new designs have major surface area.. You only need adequate float .. More float than you need doesn't equate to better wave catching .. only equates to worse performance , and as counter intuitive as it sounds , worse wave catching .. Im taking 4 new boards to Sri Lanka , all potatoish designs . My normal literage on a short board is 36 liters .. Formula is 1 liter for every 3 kg of body weight . But that is only true if I have the correct surface area .. So I usually run between 2 ? and 2 ? to get float right , consider my weight , 108 kg/240lb .. I could run 3 ? thick in something with way less area , and never in a million years could I catch waves , because of the reduced surface area , even tho float would be the same . I am running extra volume in the test boards for Sri Lanka .. around 39 liters , just 10% more , plus slightly more surface area than my regular shortboard . Why more surface area ??? Simple law of physics .. The more area , the less speed needed to plane .. The less area , the more speed needed to plane .. A surfboard only functions when it is on the plane on the surface of the water.. You can plane on your bare feet if you are going fast enough .. Look at tow in boards ? how much area do they have ?? Water skis?? Kite and wake boards ?? The surface area is relavent to the operating speed .. Low speed small waves , and you need more area .. But consider where the area is .. When you make a board shorter and wider ,you place the area in a more concentrated location under you center of gravity .. So I could have a 10' x 12" board .. Or a 5' x 24" board , both having similar area , of coarse the short one will plane better because the surface area is directly underneath you , so its more effective .. All these new super chunky boat designs are a total ****ing myth .. I validated this one 15 years ago , with 2 identical outlines , both being the same length and width .. One at 3.5 " thick the other at 1 ? thick . The thinner one caught waves easier , was faster and more responsive .. Both boards were super wide at 6-4 x 23 .. Even tho the thin one actually had not enough volume and I sank past my chest while stationary , as soon as took a few strokes, all the surface area allowed me to be up on the plane and right back at the surface .. Why did the thin one catch waves easier and perform better ??? 3 factors . 1. A thicker board naturally comes with a thicker rail , so its harder to create a defined apex where the water releases , so as you take off the thicker one has more water wrapping the rail , slowing it down , along with more rail engaged in the face holding it back . 2.. the thick one , took way more effort to bury the rail especially on the first pump while attempting to get speed , so it was naturally slower to get going because it was less responsive. 3 . you completely **** up the flex in a thick board , the thick one relied on buoyancy off the first pump , I would have to bury the rail , then wait for it to float or cork out , as it did this I could then sink the opposite rail and start to pump .. The thin one could bury the rail immediately , as well as flex into the turn , then spring out with projection and I was away at lightning speed .. Just think about what that means in terms of a quick get away ,, flexing an object and springing out of a turn or sinking an object and waiting for it to float to the surface.. Yes the volume of your board is important . But the surface area is more important . You can have not enough volume and adequate or more surface area and the board will still function . You have adequate or more volume and not enough surface area and the board will not function . So whats more important ??? It comes down to education .. Unfortunately , when most boards designers are uneducated, what do you think they will pass on to there customers ??? I struggle to comprehend why so many board designers are following this current trend .. I can only think of 2 scenarios .. 1 they are clueless . 2 , they really do know , but just want to sell more boards to a demanding market and realize they will sell more later when crew figure it out. Stupidity or greed , take your pick .. The hard part for me is stating the facts , while trying not to sound condescending or like a know it all .. As long as we clearly state the functionality of our designs and can back it up with simple laws of physics and scientific principles that you cant argue against.. Then we make our point and stick to our guns .. **** man , if the world cant get it , does that mean I will blindly ignore the laws of the universe and follow the crowd .. Been there many times in the past on other areas of design , only to be proven correct years later when the majority start to agree. Lastly , why am I only putting 10% more volume in my small wave boards ,, there is a slight compromise there.. While you can go thinner if you increase surface area , its harder to convince someone if there already on the back foot and skeptical .. So , a slight increase in volume and obviously an increase in surface area and its an easier sell .. Plus the thickness increase is not enough to compromise the flex of the board or the ability to sink the rail . So yes , even im doing it for the sake of sales , but still staying within the realms of reality, hopefully crew wake up sooner than later and we can get back to making those magic morphing sling shots. Regards BERT Ps , you can post that if you want , Swaylocks , Surfer Forum , go public with it and stir up some controversy ..

Balsaboards N.Z. said..






hey phil, surface area also gets lift from below (the waves upward and foward momentum). volume stops a board sinking too low in the water and thus needed to be paddled up out of the water and on to the 'plane' , but i find thats not as much of an advantage as being a good paddler and getting surface area into play. d

Phil27 said..
Thanks for the post - makes sense, once you're up to speed and moving . The extra foam would still help you initially get up to speed as your more above the water line though?..
I ordered a shorter, same width (albeit with slightly less rocker) with more volume than my current board - thought it might be better in smaller waves but that was not the case, sold it for an annoyingly big loss.

I guess there are so many factors to consider with surface area - length, width throughout board and rocker - it's a fine art!

Phil27 said..
Cool, thanks drip - that helps dude..

thedrip said..




Yeah you definitely don't want that extra 0.7l. It will make burying a rail and doing a decent turn impossible, while making minimal difference to catching a wave.

or you could just have a swig if water before going for a surf, gain half a kilo from the water and make up for the extra foam.

Seriously, unless you are a professional that is going to make almost no difference in your turns, and even then it's minimal.