HMAS STIRLING, Australia – U.S. Navy Lt. Cmdr. Christopher Clevenger, Submarine Operations commander, is serving as an exchange officer at Royal Australian Navy base HMAS Stirling, Australia, as part of the U.S. Navy’s personnel exchange program. The exchange program is a special duty assignment that allows Sailors to integrate into military units of foreign allies with the intent of building, sustaining and expanding international relationships. (U.S. Navy photo by Mass Communication Specialist 2nd Class Jeanette Mullinax)