U.S. Navy Petty Officer 2nd Class Ben Enderle, a diver, simulates a medical emergency requiring use of the barometric chamber during a training exercise aboard the U.S. Coast Guard Cutter Polar Star (WAGB 10) in McMurdo Sound, Antarctica, Jan. 7, 2024. The Polar Star is enroute to Antarctica in support of Operation Deep Freeze, a joint service, interagency support operation for the National Science Foundation, which manages the United States Antarctic Program. (U.S. Coast Guard photo by Petty Officer 2nd Class Ryan Graves)