What to do in a No discharge zone with y valve?

In a No Discharge Zone (NDZ) with a Y-valve on your vessel, you must ensure that the Y-valve is configured to prevent sewage discharge into the water. This typically means keeping the valve in the "closed" position and using onboard waste storage facilities, such as a holding tank. Make sure to properly dispose of the sewage at designated pump-out stations when available. Always follow local regulations to avoid fines and protect the marine environment.