What’s with the
numbers? Usually on the bottom of a surfboard? Like 7’2 x 19.5 x 2.625 and then
the one that represents volume.
The volume of foam that is rapped inside fiberglass… before cnc and computers that number did not exist, and who would care? When I was a kid if you wanted to know how a board floated you, you’d take the thing out in the water sit on it with your legs dangling off the sides and look to see how far above the water your knees were. Or, when boards became short and still weren’t cut with a computer aided machine you could sit on your board and see how much water was above your waist.
Needless to say, the board I judged where the water was from my knees or waste told me only how much float I got from the surfboard. This is fine when you want to compare how a board floats compared to another but, it tells you nothing about how the foam rapped in that fiberglass is distributed. Neither does the volume number you might see written on your surfboard.
I had a guy ask me… with concern, why of the 2 laminated and finished boards he’s just picked up from the lam shop the one 3 inches shorter than the other was heavier? These boards were in the upper 6 ft to lower 7 ft range. I mean really how can that be? One word… Volume. Yes a 6’10 can have more volume than a 7’1, if the 6’10 has a wider over all outline and is 3/8 inch thicker than the 7’1 it can calculate out with more volume. More volume means more fiberglass fabric to rap around the foam and resin to saturate that fiberglass than one with less volume. More fiberglass and resin adds weight even if the board is shorter. That tells you something if you’re interested in surfboard weight but still nothing about how the volume is distributed.
How foam volume is distributed through the length of a surfboard is pretty critical to board performance. Not just on a wave face but how it moves when paddling, including catching waves and wave entry.
You might think on a 5’11 is it possible to even know how it effects anything? Ok, what’s the performance difference in a 5’8 fish and a 5’11 tri fin? You might see similar volume between those 2 boards. Or, what about how foam distribution effects a 9’6? I’d say you may be very concerned if the 9’6 is a long board compared to a 9’10 board for heavy or big surf. You might see similar volume in those 2 boards as well.
The numbers on your surfboard give you information. It may be only for comparing the numbers you see on another board. It’s a personal thing. You have a board that you really like but want it just a bit longer or shorter but would like about the same float? Work the numbers in the computer to get a longer or shorter board with the same volume. The CNC machine will do a good job of cutting what you’d like.
But also knowing how foam volume is distributed in a boards length? That’s what will tell you how a board may respond under your feet… and weight.
D.R.
