I built this Nutshell pram in the strip method of construction for my two daughters to learn to sail and row, hence the name “Double Trouble”. I have yet to add the mast for the sail rig, but we managed to put it in the water for rowing this past week. It has the standard 1/4″ planking with a double layer of 6 oz. fiberglass inside and out. Trim is all mahogany.