Ebbster -

I've compiled the materials for a Yves-type collapsible frame. Yves used fire hose for his tubing, with PVC fittings for the end caps, ring clamps and glue to attach the caps, and a bicycle/car tube nipple as the inflater. Nothing too esoteric, the man was on a tight budget (aren't we all? ).

AFA the fore-house pram - I've long though to try making a dink using pink/blue foam (in lieu of the plywood which is in most of them), laminating it just like a surfboard once the foam was in the needed shape. Surfboards are pretty tough even with their relatively thin skins (1-2 layers of 4 or 6 oz glass), just avoid running them right into rocks - same as you would with a ply dink or an inflatable. Dings can be fixed. It'd be much lighter, and floatier.

If you haven't seen a good surfboard laminator at work, you should arrange a visit to a nearby factory and see how they do it. A 'pro' can get a board glassed to within I'd bet 15% or better of the efficiency of vacuum bagging. Waaay less of a hassle than vacuum-bagging, as did the fellow with that neat little boat.

Grist for your mental mill...