The first coaming I made was to Cunningham's dimensions. So it was about 8' long which needed a big steam box.

The second one was built for my student son Ben and was made from 2 layers rib stock ~1/4"x 1.5" which we had left over. By this stage I had realised if I made it in two bits I could steam it in a 4' long box which was much easier. I had to make two scarfs in each hoop (4 scarfs in total), but offset them on each hoop and glued them together on the former two scarfs at a time. The lip was a 1/2" x 1/2" steamed in two 4' long bits and scarfed together on top of the finished coaming. Finished size is 16"x25"

Not surprisingly this coaming was a lot stiffer than the Cunningham one which wasn't laminated. It was also much easier to make.

regards
Steve