Doweling in the deck beams is a good way to go, and I would definitely fiddle with the placement so that the the deck beams and mortises for the ribs don't overlap. I didn't have any splitting when doweling the ends of the gunwales across the grain, the splits tended to be along the grain. In the case of any splits after I was done with the operation in that area I worked in as much glue as I could and clamped it, and I haven't given it a thought since.

Why are the gunwales so short? I've never built a baidarka. Is that one of their attributes? I would make them as tall as your design allows. I think that 7/8 is a great dimension on the width. I've generally been restricted to what I get when I saw a 2/4 in half.

FYI- I used Douglas fir because I had some on hand, and I was trying to build in the spirit of the "original" and use materials I could collect rather than what I could buy. If I were wealthy I probably would use sitka spruce for gunwales. I've done it before and it works well. In all honesty though, I'm not hunting marine mammals and will probably never see a difference in strength between cedar and spruce in the real world. Once you put the skin on and it is properly shrunk it compresses the entire assembly and it is very tough. Douglas Fir, while split-prone, is very tough. Once you make it through the construction process it will give good end results.

m