The toilets are still salt water, IIRC.
I only encountered salt-water showers once on a very old amphibious assault ship (probably built in WWII), but showers are fresh water these days.
Have you tried to shower or do laundry with salt water? It leaves an irritating residue. Plus, salt water in a washing machine would rapidly corrode it.
Interestingly, the water used in the steam plant was not just distilled, but was also deionized. At the temperatures and pressures used in the steam plant, any chlorides whatsoever could cause very rapid pitting and corrosion of the piping (as in minutes). In fact, we had meters constantly monitoring the salinity of the makeup water. High chlorides were an emergency.
The ship’s distillation unit used steam to distill the water. It had very good capacity, but it broke down a lot. There was also a much lower capacity evaporator that just used an electrically-powered heater. It was pretty bullet-proof, but it only produced enough water for makeup water for the steam plant.
Once we went out for some weekly ops, and the distillation unit broke when it was started up as we left port. They didn’t manage to get it fixed until a week or 10 days later as we were driving back to port, so there were no showers or laundry the whole time. :rolleyes: I usually went to sea with about 3 weeks worth of clean underwear for situations like this.