How much moisture is a lot of moisture? I had one compartment behind the rear wheels with quite a bit of water in the bottom once. After shining a light in the wheel well, I could see light through a slight crack in the sealant. As for the other bays, never had any water issues. On some, if you don't secure the center lock on the hatch, it might leak a little in the rain or traveling in the rain. Which model do you have? The heat in ours is ducted into the bays around the water tanks and black / gray dumps. Not sure how much that would matter, but that's only 2 bays.
John and Rebecca Dickson
Emma-7 / Little John-5 / Iva-1
Full Timing Again, Rev B
2013 Ford F-350 Lariat CC LB PSD
2015 SOB TT - With OC's Awning Poles (#8)
At least in Heaven, RVs will be perfect, and I won't have to keep fixing them.