Yes, modern cruise ships are incredibly sophisticated "floating water treatment plants" that recycle and produce a significant majority of their own water. In 2026, a high-tech ship uses two main methods: Flash Evaporation, which uses the heat from the ship's engines to boil and distill seawater, and Reverse Osmosis, which uses high-pressure pumps to force seawater through microscopic membranes to remove salt and impurities. Once used, "Grey Water" (from sinks, showers, and laundry) and "Black Water" (from toilets) are sent to an Advanced Wastewater Purification (AWP) system. These systems are so effective that the resulting water often meets or exceeds the standards of municipal tap water in many major cities before it is either reused for technical purposes (like laundry or deck cleaning) or safely discharged into the ocean far from land. Many cruise lines, like Royal Caribbean and Norwegian, have achieved "Zero Discharge" goals in sensitive marine areas. Additionally, the "brine" (concentrated salt water) created during the desalination process is carefully diluted and returned to the sea to ensure it doesn't harm local coral reefs or marine ecosystems, making the modern cruise industry a leader in self-contained water conservation and management.