Here are a few things that make this hull work so well. The hull is flat all the way to the bow. The widest part of the hull is 2/3 forward, and 8" wider than the transom. i carry 54 gallons of fuel in the fwd 1/3 of the hull (in portable tanks that nest under the deck) I use a SST lifting strake across the transom with a cutout for the engine to create exagerated transom lift..
__in other words, most of the weigh is pushed max forward. The impact point of the hull is 2/3 fwd where the hull is the widest..
two opposing factors come into play here--the inherent bow lift from pushing a wider fwd hull over the water and the exagerated trasom lift from the SST lifting strake across the transom. The hull creates lift both fore and aft---that has the effecy of keeping the hull stuck to the surface. if it doesn't lift, it will not slap back down. The impact point (the widest point) uses the extra weight of the fuel along with the exagerated transom lift to crush the water and send it out the sides.
Here is a link to a stroy that was done about the 'Good Skiff' last year...
http://www.oceanskiffjournal.com/
Interesting ideas. A 19' flat-bottom dory ought to run quite well with a 25 - 40 hp motor. I have a hunch yours requires a good deal more than that.