MARINE CORPS BASE CAMP PENDLETON, Calif. - Marines with 2nd Battalion, 5th Marine Regiment, prepare to board a Modular Amphibious Egress Trainer during a helicopter dunker exercise here, Nov. 4, 2013. The training is designed to teach Marines how to egress from a helicopter in the event it crashes in open waters. The Marines conducted the training as preparation for their upcoming deployment with the 31st Marine Expeditionary Unit.