I've had this idea since ripping up my rotten, smelly, original cabin sole.
My thought: Use plastic lumber for the cabin sole.
Problem - wood rots and readily accepts and holds smells.
Solution - Plastic has neither of these two problems, however the aesthetics are not as appealing and it can be slippery.
PlasTeak and other vendors make tongue and grove plastic flooring in sizes that are comparable to real hardwood floors like in a kitchen, for example 1" thick by 2-1/8" wide.
What if I install plastic trim lumber like planks butted up tight to one another? I think it would look ok. (I'm having samples sent to me). The plastic surface can be installed with the knurled side up creating a non-slip surface.
I would not need to screw down every board, only a few as the T&G should hold the flooring in place. Plastic lumber can be worked with regular wood tools. So I can install all the inspection plates, router in the flush lift rings, etc.
Cost is comparable to or most likely, less expensive than plywood with a good sealer. Plus I never have to worry about re-sealing it - it really is maintenance free. I'd rather be sailing my boat, than working on it
Anybody else out there done a project like this?