Staff Sgt. Angel Alvarez assigned to the Warrior Training Center at Fort Lee, Va., cocks back to throw a pyrotechnic grenade simulator into the sky during a night fire event for the 2011 Department of the Army Best Warrior Competition. During the event, competitors fired from the prone supported and prone unsupported firing positions while pyrotechnics exploded all around them. (Photo by Sgt. Sean Harp / U.S. Army). 2011

U.S. Marine Corps Lance Cpl. Reagan Lodge, Headquarters and Service Battalion, Marine Corps Base Quantico, conducts water running exercises during a phyiscal training session in Ramer Hall, The Basic School, on Marine Corps Base Quantico, Va., Sept. 14, 2011. (Photo by Lance Cpl. Sharon D. Kyle)

Tech. Sgt. Milo Hinson, 3rd Combat Camera Squadron, uses a flashlight while shooting a Berretta 9mm during the night-fire portion of Advance Weapons, Tactics and Techniques training in San Antonio. During night-fire training, airmen learn how to tactically illuminate targets with flashlights and practice using night vision goggles. (Photo by Staff Sgt. Jonathan Snyder/U.S. Air Force). 2011

Servicemembers from the Iraq Air Force security forces and U.S. Air Force security forces show off for each other on the top of a hardened aircraft shelter at Sather Air Base while doing a joint patrol of the flight line. (Photo by Joshua L. DeMotts, SSgt, USAF/Digital). Baghdad, Iraq, December 14, 2011

Members of the U.S. Army Parachute Team, Sgt. 1st Class John Berentis of Yuma, Ariz., and Staff Sgt. Laura Dickmeyer of Abilene, Tex., assess the wind conditions before their pregame jump into FedEx Field in Landover for the Army vs. Navy game. (Photo by Clifford L.H. Davis/U.S. Navy). 2011

A candidate from Officer Candidate School swims through icy waters during the Quigley in order to complete a combat course at Marine Corps Base Quantico, Va., Jan., 29, 2011. The Quigley involves going through obstacles in water which includes a full immersion underwater. (Photo by Lance Cpl. Christina O'Neil/U.S. Marine Corps)

U.S. Army Staff Sgt. Patrick Reynolds, Security Forces squad leader attached to Provincial Reconstruction Team Zabul, fights racing water while holding onto a tow strap attached to an Afghan National Army vehicle stuck in the Lurah River in Afghanistan's Shinkai District. The Afghan army asked the reconstruction team for assistance because of the team's vehicle recovery capabilities and because of their working relationship after conducting frequent joint operations in the Shinkai District. Reynolds is deployed from Charlie Company, 182nd Infantry Regiment, Massachusetts National Guard. (Photo by Senior Airman Grovert Fuentes-Contreras). 2011

The Air Force Pararescue Indoctrination Course is a nine-week course that simulates ground and water survival scenarios. Pararescue training includes physiological training, obstacle courses, marches, dive physics, dive tables, metric manipulations, medical terminology, cardiopulmonary resuscitation, weapons qualifications, pararescue history and a leadership reaction course. Airmen must complete 80 weeks of training before receiving the title Air Force pararescueman. (Photo by Staff Sgt. Vernon Young Jr./3rd Combat Camera Squadron). 2011

The Joint Operation Access Exercise at Fort Bragg is a one-week exercise to prepare the Air Force and the Army to respond to worldwide crisis and contingencies. (Photo by Staff Sgt. Nicholas Pilch/1st Combat Camera Squadron). 2011

Newly commissioned Navy and Marine Corps officers toss their hats after the U.S. Naval Academy Class of 2011 graduation and commissioning ceremony. The Class of 2011 graduated 728 ensigns and 260 Marine Corps 2nd lieutenants at Navy-Marine Corps Memorial Stadium in Annapolis. (Photo by Mass Communication Spec. 1st Class Chad Runge/U.S. Naval Academy). 2011