hey i am putting in a rear deck on my boat and was wondering if anyone knows were i can get some marine plywood or any other wood for boats, or if it would be better to by wood then water proof it.
thanks.

My first boat (14' jon), the deck was 1/2" plyood untreated and it got warped. I replaced that with 3/4" and treated it with some stuff like Thompson's Water Seal. That worked well but the 3/4" plywood weighed the boat down more. You might not really need 3/4" but it has better rigidity than 1/2".

On my boat now (15' modified V jon), its a more heavy duty boat so I stayed with 3/4" and treated it again. I gave it three coats on top and bottom with whatever water sealant was cheapest at the hardware store. It was some kind of spray on stuff that dryed fast in the sun. Its been two years now and one of those years the boat was stored outside, and no problems with warping or anything.

thanks that should save me some money b/c i check the proce for marine plywood and it was like $70 for a 4x8
thanks.

I don't think that the marine rated plywood is worth the cost. Use any good outdoor rated plywood and coat it. I used three layers of Marine Spar varnish on mine. I used it on the decks and the transom that I replaced. The project is pretty new so I can tell you how it held up over the years. I did a lot of research and think this is the best way to go.

the back deck is going to be 4 1/2 feet by about 6 feet, so should i go with 1/2 inch wood or 3/4, cuz i was thinkn that might be kinda heavy for my 16 foot boat.

I would use as thin as would as you can get away with, as wood decks get heavy in a hurry. In one of the jon boats that I biult a deck for I was able to frame it with aluminium channel (you can buy it at OSH) and then used 1/2 plywood which I treated with that green brush-on sealant. It saved a bunch of weight and supported me without any problums.

Lotta ins, lotta outs, lotta what have-yous

ya i just bought some 17/32 inch ply wood for the deck an i got some pritty carpet to match. after i am done i will post pics of the project, it only cost me $36 :7