Rusty Preisendorfer is in hydrodynamic pre school !

Here are links to a couple of Rusty articles on the subject of planing in surfboards in general and Simmons boards in particular:http://www.surfline.com/blog/entry.cfm?id=41256http://www.surfline.com/blog/entry.cfm?id=41287The wide tailed pure planing concept has a lot going for it, but it's best to be clear minded about what's actually going on ( in my opinion ), and Rusty doesn't quite do that.Instead he makes several seriously erroneous assumptions which will be listed below, but before doing so I have to object to the following statement of his :"while some of you were snoozing in physics class, early board-builders were figuring things out so today's modern shapers didn't really have to"You have to be joking Mr Preisendorfer ! Firstly figuring things out is beneficial to humans, where would we be if everything had been worked out and as a consequence no one had to think ? Admittedly the current trend towards global enslavement promotes the practice of not thinking so that the corporate and fascist agendas of the globalists can be more easily implanted in the minds of their victims, but we don't want that to happen in the surfing world, we want to move towards a time when everyone thinks for themselves !We wouldn't want to be forced into concluding that you, as a corporate controller, are advocating that surfers just buy what you suggest on the basis that it's all been worked out by the people on the shaper's tree and force fed them via scientific marketing techniques. . . even though that's probably what's happening !Furthermore some of us have been doing a lot of 'working out' in the field of surfboard hydrodynamics and have come up with valid solutions which do not belong to Simmons or any other designers.Ok so here's one of the major fallacies:1) Rusty assumes that wetted surface area is related to the overall area of the board and to the overall aspect ratio of the board. That is not the case and leads to such an oversimplified view of what's happening that the resulting conclusions are false, or to be more specific have a very low truth content. He assumes that a wide tailed board has a higher aspect ratio wetted surface area but this is not the case any time that the board is on the rail

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The picture above shows that Rusty and Simmons' theory regarding board width and aspect ratio is bunkum any time that the board is on a rail. . . if it applies it only does so when the board is riding flat on the bottom.Look at the pattern of the wetted surface area, and see for yourselves !One of the principles I use which has something in common with Simmons but which looks like it doesn't ( any craft which planes must have something in common with simmons boards) , is to use a very wide planing area forward which diminishes in width to a narrow low drag displacement tail for control and which has a high aspect ratio submerged foil of infinite effective span to replace the lift which the very low lift tail surface doesn't provide.In other words there are different aproaches. The constant assumption that a wide tail always has less drag and that less fin area always means less drag is wrong, as there are lots of variables involved.Also Rusty and the Simmons crew dismiss displacement hulls and displacement based lift out of hand, ignoring the fact that displacement hulls can have a lower lift/drag ratio than planing hulls !The need to plane is more about control than it is about drag reduction..