Do toilets on cruise ships use fresh or salt water?

Until recent decades, toilets and showers on large ocean going vessels used sea water for everything, as the energy and equipment required to desalinate sea water was cost-prohibitive. read more

Today, cruise ships or any ship for that matter have been built with water treatment facilities or ocean-water desalination plant. Desalination, the removal of salt and other impurities from sea-water so that such water can become safe for human consumption. 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

All cruise lines have strict environmental regulations which they must follow, and all water from sewage, showers and sinks don't end up in sea. Every ship has big tanks with water, and it would be harder to have separate pipes for salt and fresh water (it would use more space). read more