Controlling Water Flow

Curvier surfaces bring it in and flatter surfaces push it away? Water that is. Something else that crossed my mind recently too is that you can’t speed waterflow up without slowing it down somewhere else first? Unless someone invented perpetual energy recently and forgot to tell me. This sparked a whole bunch of images (thoughts) in my minds eye that I don’t know how to put into words. Happy surfing.


 speed waterflow up without slowing it down somewhere else first?


Yes....change in velocity. Acceleration in one direction and simultanious deceleration in another. The deceleration involves mechanical drag. Will the benefits of new velocity outweigh the detrimental effects of deceleration and drag? I guess this is the Mecca.


Since matter is simply energy (semantics) and matter can neither be created nor destroyed, it stands to reason that the flow of water off of the various control surfaces we call rails, bottoms, channels, tails, fins, etc… needs proper manipulation and that water can be accelerated, that acceleration comes at the expense of deceleration in other places. Manipulating that water flow in an ever changing environment, at non-standardized angles to achieve many things like hold, turnability, speed, feel, is the crux and complication of effective surfboard design. Adding in the ridiculously inconsistent aspects of nature and humans and it’s no wonder that the perfect board has remained so elusive. 

Everything has weight, mass and volume.

Concaves create a disparity of pressure along the running surface inside/outside the concavity.

Rounds & Vee’s displace, flats plane

Straight is fast but less maneuverable

Curve lends to sensitivity

Draft is created by the relationship of deck to bottom rocker

Water is a large lazy powerful molecule that follows the path of least resistance

Water tension plays a part in varying degrees of laminar flow

Salt content varies from 3 to 12% depending upon what body of water you are in

The greatest constant is the certainty of variables.


Dean: “water has to slow down before it can accelerate?”… well, that’s like saying there has to be a premise before a conclusion.  Acceleration would be an increase of existing speed or current velocity?

More like building up the water pressure and then releasing it is what I was trying to portray in regards to slowing it down before it can accelerate. Retrothis (first reply in this thread) explained this aspect of what I meant better than I did.

Do you mean if specific criteria are met, such as ideal wave height and power for the board in question, suitable for the riders ability and weight etc the board will perform well? Not sure if that would make surfboards and surfing a good testing ground for testing the application of probabilities versus averages or something like that…

The problem with all of that is defining ideal. Since ideal is different to everyone and all of the variables thrown in by mother nature, combine that and it makes surfing a terrible medium for developing and testing any sort of repeatable performance. Even Lord’s bible of hull planing is only so applicable to surfing because more often than not, a surfboard is not planing along straight and flat over the surface of the water…but we love it so.

Thanks Doyle. I think you explained why ideal is not definable in the collective sense. Probably in the individual sense as well. At least not in surfing anyway.