151226-N-OI810-069 YOKOSUKA, Japan (Dec. 26, 2015) Hull Maintenance Technician 1st Class Edward Mountain, from Springville, Calif., performs post atmospheric gas-free engineering during a simulated toxic gas casualty aboard the U.S. Navy's only forward-deployed aircraft carrier USS Ronald Reagan (CVN 76). Ronald Reagan provides a combat-ready force that protects and defends the collective maritime interests of its allies and partners in the Indo-Asia-Pacific region. (U.S. Navy photo by Mass Communication Specialist 3rd Class Nathan Burke/Released)