Female Marines recruits navigate obstacles during Event 4 of the Crucible at Page Field, Marine Corps Recruit Depot Parris Island.

The Crucible is a fifty-four hour test event that encompasses the training the recruits have received in training, and represents the culmination of all of the skills and knowledge a Marine should possess. The recruits are only allowed six hours of sleep through the entire 54-hour event. Recruits are required to pass the Crucible before officially becoming a U.S. Marine.