Originally Posted by Yoda2

Lots of yachts have showers. Even the smaller ones (by today's standards) in the 100 foot range, typically have a shower for the crew plus one per stateroom. The crew shower is typically fiberglass, the staterooms usually tile, with the master stateroom usually something fancier. Unless your operations would practically necessitate one in an aircraft, I would probably suggest opting out as well. Plus most FBO's have descent shower facilities anyway.