What is grey water on a boat?
What is grey water on a boat? Water from onboard sinks, washers and showers is called graywater. Because boats are not connected to a permanent sanitary sewer system, graywater is discharged directly into the water without treatment.
Where does shower water go on a boat?
Because it goes back out into the environment, you must use biodegradable soap, which is usually labeled ?no phosphates.? Water from the shower drains either to the bilge or to a dedicated shower sump, and from there it's pumped outside (usually above the waterline).