PACIFIC OCEAN (Sept. 11, 2021) Sailors practice chest compressions during first aid training aboard the Arleigh Burke-class guided-missile destroyer USS Mustin (DDG 89), Sept. 11, 2021. Mustin is currently underway in the U.S. 4th Fleet area of responsibility conducting a series of exercises designed to increase interoperability and build capacity among partner nations. (U.S. Navy Photo by Mass Communication Specialist 2nd Class James S. Hong)