snip

: Question for Mike: Are the centroids necessarily the same as the centers of
: pressure? I would thing they would be a good starting approximation,
: although not exactly the same location.

snip

: Mike Scarborough
: Friendship Kayak

Hi Mike,
In short, yep. They're the same location.
Back in the 80's, I got bored and did some real-time testing of this concept.
I made a few models, about 8' long, of different underwater profiles and plotted the centroids. (the hard way, pre-PC)
In windless conditions, pushing with a stick anywhere on the vertical line through the centroid moved the models evenly, no lee- or weathercocking as such. If the point of contact is level with the centroid, there's no change in attitude in any axis.

The same principle is used by tugboats to bring some large ships alongside in close quarters.

Hope this helps,
Mike Savage
South West Cork