Sailors scrubbing a flight deck with push brooms.
Source: http://en.wiktionary.org/wiki/File:US_Navy_041118-N-5345W-029_Sailors_assigned_to_the_Air_Department_conduct_a_Scrub_Exercise_(SCRUBEX)_on_the_flight_deck_aboard_the_Nimitz-class_aircraft_carrier_of_USS_Harry_S._Truman_(CVN_75).jpg