Re: How far will the plywood bend?
I faced this exact same problem in the same location with Hornpipe, except that I was trying to cup 9 mm okoume. I couldn't do it, even with steaming it. I ended up doing what Yeadon suggests, using, in my case, 3 layers of 3 mm ply for the last 3 ft of plank. I used the boat itself to clamp the whole rig together while gluing and it was quite a lashup, but it worked. Here it is after laminating and trimming and cutting the gains
"A man who is not afraid of the sea will soon be drowned, for he will be going out on a day he shouldn't. We do be afraid of the sea, and we only be drowned now and again" Arran Islands Fisherman