ABSTRACT Ballast water carried by ships keeps them upright during loading and offloading operations and provides balance, stability, and trim during sailing. Because ballast water is loaded from the surrounding port or coastal waters, organisms in the ballast water sometimes establish populations resulting in biological invasions, which may have severe ecological or economic impacts. Ballast water is typically carried in dedicated ballast water tanks located around cargo tanks/holds, in forepeak and aft peak tanks located near the bow and the stern of the ship. Because ballast water is taken on board from the surrounding port or coastal waters, it can contain a diverse assembly of marine life. The coatings applied today within ballast tanks are required to conform to the IMO(1) Resolution MSC.215(82), "Performance Standard for Protective Coatings for Dedicated Seawater Ballast Tanks in All Types of Ships and Double-Side Skin Spaces of Bulk Carriers" (PSPC/WBT/BWT).2 This standard is intended for use by shipbuilding companies, shipping companies, ship personnel, coating companies, cathodic protection (CP) service providers, and ballast water treatment (BWT) suppliers to help prevent corrosion in ballast water tanks. Should any deterioration occur within the control a retest shall be required. [...]a comparison of the final test results shall be made between the test samples in treated water vs. untreated water.