Abstract: Exemplary inventive practice replicatively tests the effects of cleaning processes applied to marine hulls coated with biofouling-control substances. A sample (e.g., antifouling-coated panel) is coupled with a trolley that is linearly moveable via trolley wheels upon two parallel tracks provided along the length of an open rectangular box-shaped tank, partially filled with natural or artificial seawater. The cleaning element (e.g., brush bristles) points vertically upward in a stationary position atop a motorized cleaning unit installed proximate the bottom of the tank. In accordance with the trolley's horizontal movement, and while the sample and cleaning element are immersed in seawater, the sample traverses the cleaning element in a contactual manner that mimics underwater cleaning dynamics for a hull surface.