JEM Watercraft

I am building a Sasquatch 16-33 and was wondering if I position the yoke, thwart, and front seat like this drawing using the yoke and the front seat as thwarts. Would this be strong enough or would I need to mount another thwart somewhere between the yoke and bow?

Another wouldn't hurt. But your gunwales look stout so I think you should be ok. Check when you strap it down to your roof rack. If there's a lot of flexing on the one end, then you might want to considering adding one more.