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dedicated ballast puaps. The saae puap and the saae external hull 

 openings are normally used to take water Into (fill or ballast) and 

 remove (discharge or deballast) water from a vessel. The ballast intake 

 is normally covered with a steel plate (a grate or strainer) with 

 numerous holes of 1.0 to l.S cm diameter. Water may also be gravitated 

 in or out of a tank or hold. 



A vessel may have water from multiple sources, with water from different 

 sources mixed or unmixed different tanks. In biological terms this 

 means that a vessel may accumulate organisms frc» multiple ballastings. 

 Container ships represent one of the best examples of the constant 

 (daily) movements of ballast water, often taking up and discharging a 

 quantity of water in a "Johnny Appleseed" ("Johnny Clamseed") fashion, 

 wherever they go. Host vessels keep some type of record of ballasting 

 operations, but there is no uniform industry standard. 

 Hater is carried by a vast variety of vessels and held in an impressive 

 variety of tanks or holds. Ballast carried can range from hundreds of 

 gallons in sailing boats and fishing boats to tens of millions of 

 gallons in commercial cargo carriers. 



Vessels are said to be in ballast when they have ballast water and no 

 cargo aboard. A vessel is with ballast when cargo and some ballast water 

 are aboard. Vessels on their "ballast leg" normally carry the most 

 ballast water. Vessels on their "cargo leg" also almost always have 

 some ballast water, but in much smaller amounts. 

 Inbound vessels that have released their ballast water prior to or 

 during cargo loading, and outbound vessels with full cargo loads, may 

 have sufficiently little ballast on board that the mariner would report 

 a ballast condition of "No Ballast on Board" even when some water 

 remains. While the amount of water in a loaded vessel may be only in 

 the hundreds or thousands of tons, from the point of view of a marine 

 biologist these volumes of water (tens of thousands to hundreds of 



