One coat might suffice if you could be sure it was perfect -- with no pinhoples or cracks that water could penetrate.  But this is not a place to economize -- especially the compartments under the seats that could contain standing water and might be hard to inspect. I say to use a minimum of three coats. You want that wood protected forever!  

OK, second coat on today. Glad I did. Still debating 3rd coat, though.

I thought the compartments under the fore & aft seats was supposed to be water-tight unless you added an access port? (The ports are supposesd to be water-tight, though.) I also thought the access port was there to dry store small items. Did I miss that its really for access to remove the standing water?

I do see you wrote "could" contain standing water, not "will." I guess the question is, "Should I expect water to leak into those compartments."

Frank

Water will find a way...  Even condensation can cause a problem if those tanks remain sealed without ever having a chance to air out.   

Hooper,

OK, that makes sense. I guess I'll have to get a deck plate or 2.

Frank