Deep in the Skull Cave is an indoor waterfall and bath tub which the Phantoms uses. The first time anyone was seen washing was Diana in the 'Phantom Goes to War' storyline. That shower however was outside the Skull Cave and never seen again.

In the 1980's, the indoor shower was shown. It has not been shown often. Since the mid 1990's there has been a bath also shown. Assuming the shower and bath are in the same room of the Skull Cave.