Ballast water that does not produce a visible sheen when discharged defines:

The definition of ballast water that does not produce a visible sheen when discharged refers to the concept of "Arrival Ballast." This term is used in maritime operations to describe the ballast water that has been taken on board a ship before arrival at a destination port. This type of ballast is typically clean and has not been contaminated with oil or other pollutants, which is why it does not produce a visible sheen when discharged.

The importance of this distinction lies in environmental regulations that aim to prevent pollution from vessels. Discharge Ballast refers to ballast water being released from a ship, which may not necessarily imply it is clear of contaminants. Polluted Ballast specifically indicates ballast water that contains harmful substances, leading to sheen or visible pollution. Intermediate Ballast denotes ballast taken on during a voyage to maintain stability, which may not be reflective of the condition upon discharge either. Therefore, "Arrival Ballast" is correctly identified as the type that indicates a clean state upon discharge.