: I have plans for a stitch and glue decked canoe and I am thinking about the
: fiberglass layup. The core is 4mm plywood and the plans call for 6oz glass
: skins. I am interested in a more durable "expedition lite"
: layup, possibly incorporating some s-glass or kevlar. What would the
: experts here recommend? Thanks for your replies!

If you want more strength, just add another layer of glass. Kevlar and/or S-glass are used on canoes/kayaks to save weight primarily, not for adding strength.

Bill H.