I have a different viewpoint on the widepoint… riding characteristics are not dictated by the location of the widest point at all, any more than any one other single variable.
In naval architecture, there is the “Curve of Areas” which describes the cross sectional area of a hull at 20 equally spaced sections along the length of the hull. It has significant influence on the characteristics of a displacement hull. Let’s take that concept to a surfboard, and instead of cross sectional area (and the resultant volume), let’s look at the distribution of width (area) on the hull as you move from one end to the other.
You have to stand somewhere; the curve of areas determines where, because you need sufficient lift to balance your weight. (Of course, this is a static situation, but the dynamic situation follows intuitively). “Modern shortboards” turn so well because the curve of areas makes you stand relatively far back on the tail, where the pivot point is located, regardless the number of fins. Coupled with low mass (narrow, thin) at the nose, there is relatively little inertia to overcome when you want to turn. So… “modern shortboards” turn quickly, and it’s not really about where the wide point is.
The same “modern shortboard” has distinct disadvantages compared to the single fins which the older of us rode at one time, but marketing (fake), decreased turning radius (real), and the desire to "surf like Bruce/Andy/who-da-f**kever, have combined to make them the board of preference.
For all that, my almost-all-the-time board is a 7’10" x 20.5" x 3" round pin single fin. Right out of the 80x, maybe, but it’s more agile than I am, it outpaddles most of the normal run, and has sufficient rocker to have saved my bacon, lotsa times, lotsa places, lotsa years. It hasn’t snapped when I get stuffed, and for all that, it’s over five years old and still in far condition. Anyone get that kind of life from a “modern shortboard”?
