Here's a little food for thought. It is possible for a ten or twelve pound board to have an equal or better surface area to weight ratio, than that of a five or six pound board. Even boards that weigh as much as twenty pounds can get surprisingly close. I take a look at it as a predictor of the potential performance, for a given board. It was a real eye opener for me. Do any of you do the same, or something similar? Just curious.

Mr T., What is the calculation you use? Doesn't this directly correspond with displacement?

It seems this A.M. I'm a knucklehead.

Alive since 1958.

Tblank,

What I use is a real ''Ballpark'' calculation. What I arrive at is the number of ounces of board weight per square foot of surface area of the board. Truth be known, it's probably more revealing to calculate the combined board and rider weight per square foot of surface area. Calculating displacement probably gets you into the same ''Ballpark'',however I just felt that surface area (planing area) was more appropriate to consider. I found it interesting to compare different boards that way. My thinking was that displacement relates to static floatation, while surface area relates to dynamic planing. All that said, we all know we don't use 100% of the surface area of the board while riding. That's why I say it's a ballpark calculations.

Well said Mr T. This could get very complicated.

My bean don' work li' dat. (Complicated....that is.)

Surface area is determined by design, weight is volume x density. It's not surprising that a heavier board could have a higher ratio; bigger, thicker boards have proportionally more mass in their (hopefully) lighter cores. The smaller and thinner boards diminish the weight savings available in core.

I do consider weight and planing area, which I figure averages about 1/2 the board on slow waves and less on bigger, faster waves… about a third.

Roy’s $41,000 monster is like, 27 inches wide, and the board alone is 25 lbs… with a ton of rocker? What does that tell ya?

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Roy's $41,000 monster is like, 27 inches wide, and the board alone is 25 lbs... with a ton of rocker? What does that tell ya?

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That tells me that Roy has an entry-level model (compared to his $400-500K line), and that it must be faster than a speeding bullet.

oops… left out a zero. Ha!

But yea… what’s the ratio on that sucker? could it be the same as a psb? Even when you compare a highly rockered, featherweight hplb to a classic log, you stll follow the same patter… more wetted surface for a heavier board…riders being equal

bill,

problem with that is; the consistancy of foams............unless you're talking kookboxes or something else.

ya ,i've thought of it and guesstamated volume over area................it comes with the terrain.

herb