When I was a kid my best friend had a 14' kayak that had metal ribs and spruce stringers. We discovered that it is a good idea to carry some wide adhesive tape with you. I had one that was 21' long that I hauled on the roof of a 64 VW beetle. That boat was all wood and canvas. It was stable enough that one person could steady the boat and the other could stand to cast. Of course, my balance was much better then than now. It was kinda neat to watch the front of that boat flex in the waves.

They are not expensive to make. Use the lightest weight cloth you think you can get away with. If you use cotton don't get carried away stretching the fabric over the frame. Just get it smooth. It will shrink enough when you paint it to seal it.