[Legless]

Hi Stephen,
I grew up in a boat shed where my father and grandfather built clinker and laminated ply launches for hire on the NSW Central Coast. So my information is old and probably out of date and could also be specific to NSW. The Marine ply we used for floor boards was ½” and for the transom would have been at least ¾” depending on bracing and this was for putt putts not outboards, though these days any of the surviving boats would have outboards. Unfortunately the days of the Tasmans, Simplex, Chapman and even Oldes have long gone. Always use Marine ply in boating, ‘normal’ grades of ply rot extremely quickly even when glassed due to the humidity. I don’t know what timber the marine ply consisted of except the veneer, and that was Coachwood (Ceratopetalum apetalum) this is a widespread rainforest tree of SE Queensland to SE NSW. Coachwood was good as it varnished quite nicely, as I said this may have been specific to NSW, I’m not sure.

I was down at our old boatshed the other day and noticed the owner was repairing one of the half cabin boats with what looked like 1” ply but it was very pale with straight grain, it certainly wasn’t Coachwood. Hope the above info helps.

Cheers

Legless