SundanceUK

Have a look at the condition of the large blank grommet to the right of the snorkel. I found a line of corrosion around mine that had lifted the grommet seal and allowed water to seep through. I cleaned mine up and run a circle of touch up paint around the hole before refitting the grommet.
The top of the carpet will be dry as there is a plastic skin between the top of the carpet and the foam underside. Any water collecting on the top of the carpet will naturally dry up through evaporation, however any finding its way under will never dry out because of the plastic membrane.
To dry the carpets I lift the carpets back and squeeze out most of the water and use a fan heater to dry the foam out.

Sundance