Do cruise ships use recycled toilet water as drinking water?

The short answer is NO! I've written about waste water on cruise ships in my blog - Crew's Ship.com - How is waste water treated? - but I've copied the main points here. read more

Grey water represents the clear majority of the waste water discharged from a ship, and as such any chemical used such as with shampoos, body washes or laundry detergents are heavily diluted before being discharged, and of course further diluted as the ship sails through the ocean. read more

Today’s cruise ships use potable water in toilets and showers, thanks to engineering ingenuity resulting in onboard water desalination systems. Ocean water desalination plants remove salt and impurities from sea water, rendering it safe for human consumption, providing a much more pleasant cruising experience. read more

On a cruise ship it would be fresh presumably, to avoid corroding the hell out of the pipes and not having to run separate plumbing to each bathroom. A quick googling seem however to indicate that at least some aircraft carriers used sea water in the toilets and the fire extinguisher sprinklers. read more