: I've got a few pictures

One of them is of the computer model for the seat. This raises
an interesting question. How do you get the initial computer
model for your backside (US: butt) ?

I would think for most people lacking 3D modelling skills and
an intimate knowledge of their own anatomy, the solution would
be to sit onto a bag of polystyrene spheres, then suck all the
air from the bag to solidify it (like they do for stretcher bases
for evacuating spinal injury cases), then mark a series of parallel
lines and finally take measurements on those lines with a big
contour gauge. Is there a more ingenious way that I haven't
thought of ?

And for the detractors, why would this be any less comfortable
than the normal fibreglass seat you get in most composite boats ?
I have a hard seat in my bought boat, and a moulded foam seat in
my home-built boats. I've never found any need to pad out the
fibreglass one, and I've probably sat in that for longer trips
(up to 20 miles in one sitting when we found the swell too big
to land). The foam seats tend to start to get uncomfortable
after a few miles as there is less air circulation in my pants
and more insulation which makes it sweatier...

Andy