Besides retention of ballast water onboard or use of approved onboard ballast water treatment equipment, what is another acceptable means for a vessel to be in compliance with the ballast water management regulations?

Correct Answer: Option D — Perform a complete ballast water exchange in an area no less than 200 nautical miles from any shore prior to discharging ballast in U.S. waters.

Under 33 CFR 151, vessels entering U.S. waters must manage ballast water to prevent invasive species. A mid-ocean exchange at least 200 nautical miles from any shore is a recognized standard, as it replaces coastal water with deep-ocean water, which is less likely to contain organisms harmful to U.S. ecosystems.