I recently restored a 16' v hull which you can see on my thread about it.  It was brought to my attention that the OSB ply I used was probably not the best choice.  I did seal it with resin but I'm not sure how well that worked, some pieces got plenty but I fear I was running low by the time I got to the front deck and it may have gotten short shrifted on resin.  I am willing to remove the carpet (just held on by staples anyway) and seal the wood up with additional layers of waterproofing to avoid problems down the road, but, just so I am clear, if I get it fully sealed, the wood should be fine correct?  My understanding is that structurally it is just as good as ply but just not as water resistant?  Not that I plan on getting it soaking wet anyway (I don't care for fishing in the rain) but I'd like to know it will at least last 5-7 years.  I plan to use a spray on sealant the second time around.  Opinions?  Thanks.

It'll work as long as it isn't wolminized. Wolminizing chemical becomes an acid that eats aluminum when it contacts water. Otherwise you're good. If you want to tackle the mess of resin, more power to ya, but you can use Thompson's Water Sealant and get the same effect with no mess.

How many wooden boats have you seen that were built with OSB? I would use some clear polyurethane , 2 coats, to seal your decks It will provide a durable finish even under the carpet.

If moisture just looks at OSB it's as good as gone.

Pickup some minwax helmsman urethane at Walmart.  The stuff is tough, is specifically designed for outdoors use and flexs.  

Clearly, I know I made an error, so the rhetorical question was really unnecessary. Nonetheless, I'd like to be able to fish out of it for at least a few years before I have to do it over again, so I was just looking for some advice. You did give some of that, so I thank you. I ended up sealing it with rubberized undercarriage spray, which I had lying around. Hopefully that will provide some sound damping as well as sealant. Next time I'll use the marine grade ply.

How many wooden boats have you seen that were built with OSB? I would use some clear polyurethane , 2 coats, to seal your decks It will provide a durable finish even under the carpet.

Don't coat the outside with fiberglass or anything else that will keep the wood from drying out if/when it does get wet on the inside and it will.  Google the "Rot Doctor" and look at their Clear Penetrating Epoxy Sealer.  I don't know if it will work on OSB but it will rot proof wood and plywood.  I used it on a fishing boat deck that has sat outside in the weather for several years and it is still holding up.  It is expensive and may be more than replacing the OSB but it would save you the labor of redoing the deck.  It penetrates the pores of the wood and keeps it from rotting on the inside.  Does a much better job than thinned down resin, I have used both.