No glass on the outside. It is just 4 mm and 3 mm marine grade ply (multiplex). Only the decks between the beams has a single layer of glass on top of it to make it more robust under trapeze hooks and other sharp objects hitting it. And they HAVE ! The 4 mm ply with a single layer of glass is very damage resistant, more so then any modern foam cored glass hull.

Actually, my ply F16 is pretty tough and you handle it just as carefully as say an F18; but in my experience leasurely sailors often try to be as negligiant and obusive as possible, hence my advice.

Wouter