Hello, I have a project that I would like some input/suggestions. I have a boat that the deck doesn't drain properly(the new motor is lighter). The deck is solid, so I was thinking of possibly laying pvc foam over the current deck and taperring it so it drains and cover with 3 layers of fiberglass? Do you think 3 layers of 8.5oz cloth(I'm in the US, so aprox. 290g cloth) will be good...too thin...or overkill? It is a center console, so I would have marine plywood laminated under the helm seats to mount/support. All suggestions welcomed.

A lot of if depends on the shape, size and use of the deck, if its going to be subjected to foot traffic, fishing poles, waterski's etc then most decks will be around 3mm minimum to stop penetration through the skin. A 3mm skin with be just over 1350gsm of CSM (about 4kg/m2 & 3 layers of 450gsm), if using carbon then potentially you could get away with less, but 200gsm carbon is about 0.2-0.25thk so you'd need 12-15 layers for 3mm.

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Thanks for the reply chris,