A U.S. Navy Sikorsky MH-60S "Seahawk" helicopter attached to Helicopter Sea Combat Squadron 21 (HSC-21) "Blackjacks" lifts pallets of supplies from the flight deck of the Military Sealift Command fleet replenishment oiler USNS "Walter S. Diehl" (T-AO-193) during a vertical replenishment with ships of the USS "Essex" (LHD-2) Amphibious Ready Group in the South China Sea. The dock landing ship USS "Rushmore" (LSD-47) is steaming aft of "Walter S. Diehl".