150821-N-UQ938-097 DA NANG, Vietnam (Aug. 21, 2015) Lt. Cmdr. Marddi Rahn, a Navy nurse embarked aboard the Military Sealift Command hospital ship USNS Mercy (T-AH 19), demonstrates how to use a ventilator at an advanced cardiovascular life support subject matter expert exchange at Da Nang Central Hospital during Pacific Partnership 2015. Mercy is in Vietnam for its fourth mission port of Pacific Partnership 2015. Pacific Partnership is in its 10th iteration and is the largest annual multilateral humanitarian assistance and disaster relief preparedness mission conducted in the Indo-Asia-Pacific region. (U.S. Navy photo by Mass Communication Specialist 1st Class Trevor Andersen/Released)