Exchange
Exchange means to replace the water in a ballast tank using one of the following methods:
(1) Flow-through exchange means to flush out ballast water by pumping in mid-ocean water at the bottom of the tank and continuously overflowing the tank from the top until three full volumes of water has been changed to minimize the number of original organisms remaining in the tank.
(2) Empty/refill exchange means to pump out the ballast water taken on in ports, estuarine, or territorial waters until the pump(s) lose suction, then refilling the ballast tank(s) with mid-ocean water.
Source
33 CFR § 151.2005
Scoping language
Unless otherwise stated in this section, the definitions in 33 CFR 151.1504, 33 CFR 160.202, and the United Nations Convention on the Law of the Sea apply to this subpart.