Another advantage of the intermediate frame, is that it could be used to suport the sides of the coaming. Do you think it would interfere with the gunwales and chines bending to a fair curve? Would it be better to fit the "extra" crossection after the frame is, at least temporarily, assembled?
Thanks,
Will

: I think the intermediate frame is as valid as any other idea, and will let
: you use shorter/thinner seat slats. A couple of ribs fastened to the
: inside of the gunwales, passing under the seat slats to support them,
: might be an interesting approach. Depending on the width and depth of the
: hull, and its stability characteristics, raising the COG by 1/2" or
: 3/4" may not adversely affect its handling enough to worry. If you
: are building narrow, tippy hulls, that won't be a good idea unless your
: customers are accustomed to paddling such craft!