Re: Musty boat smell under floor
In addition to the above suggestions, If you've had a wet bilge...you might also have slime, mold, growth growing on the underside of the floor and floorboards. Do you have floorboards in the head too..for a shower? You might want to rig something to reach in under the floor and scrub the underside as far as you can reach. If you can.
Bene's suggestion of filling the bilge with bilge cleaner and going sailing should get the rest.
I took my shower floorboards home one season and scrubbed them and cetoled both sides...the underside was just raw wood... ?
It took me several seasons after buying the boat to get all the musty odors out. Last weekend I had guests aboard and they commented on how dry and odorless a boat it is now.....it took a lot of work cleaning, and hunting all the sources down.