Sgt. Ysuf S. Sesay, Drill Instructor School student, is evaluated on unit leader close order drill Tuesday. The depot?s Drill Instructor School shares Shepherd Memorial Drill Field with recruits in training. The drill field is an important part of a Marine?s training and is highly respected ground. - Sgt. Ysuf S. Sesay, Drill Instructor School student, is evaluated on unit leader close order drill Tuesday. The depot?s Drill Instructor School shares Shepherd Memorial Drill Field with recruits in training. The drill field is an important part of a Marine?s training and is highly respected ground.