Built down Skeg Built
See the difference in the turn of the bilge of both models? Basically when the plug is created the built down method planks right from the shear, to the turn of the bilge, and onto the keel in fluid arcs.
A skeg built boat is planked from the shear to the turn of the bilge and centerline. Then a square series of stacked planks are put on the centerline to create the keel area.
Skeg built boats are easier to build plugs for, and are the old way of building a wooden boat because the keel can just be solid hewn timbers with a few holes drilled in them and along the length for the shaft.
Supposedly skeg built boats are "faster" but I don't believe it for a second. Plus they tend to pound the fillings right out of your teeth since they ride up the wave then come crashing down, with the advancing water slicing right up along the keel then ramming full force into the bottom of the hull. On the built down the water starts being diverted from the subtle slant of the keel, hits that reverse curve and slides up alongside the hull giving a much softer ride (your wife won't be bitching about being thrown around like a rag doll) so you have a much better boating experience.
An added benefit to built downs are that you get MUCH more room under the deck. The engine can be slid further down into the boat, giving more positive ballast and you can fit more goodies down there. Maybe instead of a 20 gallon water tank you can have 40, instead of 200 gallons of fuel you now can have 400, you might not consider the space below deck because you don't spend much time there but it is a godsend if you ever have to be down in there because something went wrong. No one likes to play bilge rat, and a stuck bilge rat is one unhappy fellow.
True story: Myself and another were heading to a race in somewhat turbulent weather, seas were in the 2-4 range and the wind was howling just a wee bit (sustained 20's) I in my NB36 and he in his CB 34, both have the same power - 410 Sisu and both with comparable speeds. Both of us cruise at 25 mph but only one of us was able to do it that day, because the terrible pounding made them slack back to around 17-18, and even at that reduced speed it was still bouncing at a fairly good clip. Up ahead the nose was just raising and lowering with the roll of the waves, no jostling, no banging, just a sweet soft ride.
Later on that day when I decided to continue East while the rest of the fleet tucked tail and ran back West, I found myself in increasingly worse weather with seas creeping up steadily around the 10 foot mark, winds now pounding the side curtains at 30 mph I too did have to throttle back quite a bit. But not due to any adverse effects of pounding, rather I was running with the waves but I was going much faster than they were and the six year old, on her first real big boating adventure, wasn't too keen on the pitch poling sensation of cresting the wave and plunging down the other side. Throttled back and it was surfing from there, only jostling was from the random rogue wave that bashed against the transom and rained down a bit of salty sunshine upon us.
I can't comment on the ride of a skeg built boat in those conditions because no one wanted to come and play, so we have no data. It was an awesome trip and I'd do it again in a heart beat. Only this time I would check my propeller and take the damn rope out!