Students were tested, ranked by ability, and required to wear colored shorts that reflected that rank. White shorts were the rookies who had to do a minimum of six pull-ups. (Today, a Marine can pass a physical doing only three.)
Navy Blue shorts were the highest rank. To earn them, a student had to do 34 pull-ups and carry someone on their back for five miles. Only 19 students in the history of the school ever earned them.