Plywood floor gets inexplicably wet, what could possibly be the cause?
Sorry im a little confused on what and were your house is loctated? Piers like a beach house over water? The plywood is the floor it's self? Or are you looking at the ply from under the floor?
The only thing I can answer is long term will be mold if water continues to sit on ply I wouldn't put any laminate down unless you figure what or were your water issue is and if it is a beach house I will not recomend Laminant floor I would recomend tile.