: Dave, I have framed up a Sea Rover to build strictly for rolling.
: I've used 1/2" ply and used WRC for all longitudinals. I
: followed Tom Yost's recommendations for the scantlings. It all
: goes together as advertised. All considered, I'm a little
: concerned that there is too much sag and spring in the boat due
: to the lightness of the gunwales, chines and keel, especially
: with the WRC. I saw on Tom's site another design with a rather
: heavy person (not me, I'm only about 155#) and the stern was
: actually completely out of the water and the boat looked like it
: was sagging significantly.
: What was your experience with the Sea Rover along these lines? I
: cannot imagine the skin adding that much longitudinal stability
: in the frame, but then again, this is my first skin-on-frame
: attempt.
: Cheers and happy paddling, Wil.

I weigh about the same - and Tom's scantlings are just fine. I've built plenty of his boats, including the Sea Rover, and never noticed any sag or spring in them. Each piece of wood is different, but it should work just great for you. The Sea Rover is a fine boat, which I paddled for about a year - and sometimes almost daily - in a variety of conditions.
Perhaps the pic you saw was one of his aluminum framed boats, which are considerably more flexible and definitely sag. Tom came up with various schemes to stiffen some of those frames.

Too late for you, but I feel Tom's Rolldarka to be superior to the Sea Rover in every respect. A little more leg room, much more stable, carves turns well and rolls even easier. To be fair, I modified my Sea Rover a bit, making it both shorter and narrower, and that was likely a mistake, handling wise. You'll likely be very pleased with yours.

Looking forward to seeing your boat!