I finally did it. Finished the EA kayak with some deviations from the traditional norm, painted it and headed out to the water to see how it paddled.
The big question was what sort of speed a flat bottomed boat could be paddled.
I had my GPS with me. At the start of the test while I was still fresh, I managed to get the boat up to 5.6 mph. Cruising speed seemed to be between 3 and 4 mph. I did my usual two mile circuit once around Ballena Island. Wind was variable, maybe up to 15 mph and wind blown waves were about 1 foot max. So not much of a rough weather test.
Overall, the boat seems to move about adequately. Turning with the flat bottom is easy. The boat responds quickly. I thought that staying on track might be a problem but it turned out not to be. The boat had no particular tendency to turn into or out of the wind and it had adequate length so it wasn't yawing right and left with each stroke. Paddling both down and upwind was possible without any undue steering effort required. So all in all, the boat performed well. I would still like to take it out on a rough day when waves are more like two feet, like a normal summer afternoon on the bay.
I ended up using the 120 inch paddle for most of the trip since it seemed to be a better match to the boat than the 88 inch paddle which required more effort to reach the water.
Overall, I felt that I needed more experience with the boat. The initial outing left me feeling that its weight and speed was such that I need to discover some more positive attributes for the boat or it would not get much use.
Speed is of course an ill defined measure. What matters is efficiency. Overall, the width and flat bottom of the boat are a combination that require a good deal more effort to make the boat go than just about any other kayak style that I have built. If I were to build another version of this boat, I would probably decrease overall width and increase flare to the sides from the 10 degree flare that I put into this model. Increased flare would decrease the width of the bottom. I probably would also go with bent ribs to reduce weight of the boat and have some V in the bottom. With lighter weight and less resistance to movement this style of boat would be adequate for recreational use.
As I mentioned earlier, the boat also needs some rough water testing to see how the flat bottom handles going over waves.