Trend Timber in Windsor (02) 4577 5277 sell beautiful marine grade gabboon (Okoume) plywood with equal thickness plys (imported from Israel). They also sell Hoop Pine and Pacific Maple in marine grade but the Gaboon is the lightest and (in my opinion) the best looking. I'd strongly recommend you don't use the luan or any exterior grade plywood. For a small saving in plywood cost you¹ll probably spend more on epoxy and fibreglass trying to get the hull fair and end up with a heavier boat.