USS Ralph Johnson (DDG 114) conducts an underway replenishment (UNREP) with USNS Rappahannock (TAO 204) in the Pacific. UNREPs are essential in allowing our U.S. Navy ships to remain underway at sea longterm in support of our national interests promoting prosperity and security, deterring aggression and protecting the American way of life. UNREPs involve the transfer of all consumables from supply ships to the customer ships while both are underway. Items such as fuel, food, ammunition, repair or replacement parts, mail and personnel are routinely transferred atsea.