Marines from Tank Platoon, Alpha Company, Battalion Landing Team 1/1, 13th Marine Expeditionary Unit, perform daily maintenance on one of their M1-A1 Abrams Main Battle tanks while aboard the USS Green Bay, March 11, 2011. The Marines perform this maintenance to prevent salty and moist air from corroding the metal on the tanks. The ship has the capability of storing a variety of vehicles and cargo such as tanks, amphibious assault vehicles and quadcons.