Been on the Gulf Coast for decades with sail boats and RV's.
Get a house-type dehumidifier, set it SECURELY on the galley counter draining into the galley sink, set it at 50% humidity and forget it. Done this on every sail boat and RV we have ever had.
Sorry, though an A/C will remove moisture (usually drips off the roof), the evaporator coils stay WET. The filters are poor, so you end up with MOLD growing on the wet, dirty evaporator. Difficult to clean (from the roof only, and only after removing the cover and all the screws holding the cover for the evaporator).
Since a dehumidifier has both hot and cold sides, far less chance of mold. And really easy to clean.