A marine oily water separator is a specialized piece of equipment commonly found onboard ships and vessels. Its primary function is to separate oil and other contaminants from bilge water, which is the wastewater that accumulates in the bottom of the ship's hull. Bilge water often contains oil, grease, fuel, and other pollutants that can harm the marine environment if discharged directly into the sea. The oily water separator helps ensure compliance with environmental regulations by treating bilge water before it is discharged overboard.