Charlie Co. candidates from the Officer Candidates School, participate in a medical evacuation exercise during a second Small Unit Leadership Evaluation aboard Marine Corps Base Quantico on July 25, 2013. The event evaluates leadership, command presence, communication and decision making. - Charlie Co. candidates from the Officer Candidates School, participate in a medical evacuation exercise during a second Small Unit Leadership Evaluation aboard Marine Corps Base Quantico on July 25, 2013. The event evaluates leadership, command presence, communication and decision making.