Those boats are definitely flat bottomed. Narrow bottom and rockered,
but very flat. Those are rowing dories and sailing dories though. The
only power dory I saw was an adaptation of the others.
With the HP requirments you mentioned, I assumed you have a planning
dory. It would have a flat bottom with no rocker, flared sides, and a
high bow that looks like those on the website. But it wouldn't have a
narrow or pointed stern like those shown. The transom would look more
like a traditional outboard skiff.
Can you find a photo online that looks similar to your boat?
But like somebody upthread already said, on a boat that small (16'), a
canvas dodger sounds like a better way to go no matter what the hull
design.

Rick

On 2 Feb 08), Paul wrote:
Thanks for the link Don and you are right, nothing like my boat. Mines
quite flat bottomed.

Here's how they're made in this area...http://www.doryshop.com/thumbnails.html