While attending a class with George Gronseth Summer '97, I had the opportunity to ask some fundamental questions. One of those questions was, "What makes boats Carve turns?"

I'll admit that I was recovering from the death of my mother and therefor my brain was a bit more than foggy, but the principle made sense and still does. What I wanted to do then and couldn't was envision what happens to the shape of the hull in contact with the water. Below you will see a photo of a model I made on my lathe, then cut at approximately 45 degrees to simulate leaning to carve a turn.

Essentially, When a boat "carves" it does so because by leaning it, the hull cross-section becomes more like that of an airfoil. The same thing that makes an airplane wing generate lift*.

Lean LEFT Carve RIGHT, or, Lift [your right leg] Carve RIGHT...

While attempting to make a model that CLEARLY showed this shape, I came across some interesting information, like how adding weight affects the hull shape as exemplified by removing varying amounts of the model...

This holds more true in a boat with minimum rocker. In a WW boat for example [I am told] one can tend to carve a turn in either direction when leaned.

In a recreational kayak, due to their generally larger beam, my experience has been that they don't lean very well at all-they tend to have high initial stability with I suspect far less secondary stability-and therefor carving is something not encountered...

Yea, I know, I suppose one could do the same thing with a good 3D CAD program in a tenth the time. I don't know CAD, I know WOOD!

*[the rounded surface causes a low pressure area in relation to the flat surface. The flat surface allows a higher velocity of fluid than the curved one. Of course there is a direct relationship between pressure and velocity, one can demonstrate that with a water hose should one choose]

Material Copyright © 1998 Tom Weese