conducted at TBS Basic Officer Course (BOC) Introduction and background After earning a commission, new Marine Second Lieutenants (Unrestricted Line Officer Marine Lieutenants) complete the Officer Basic Course prior to beginning their job specialization (Military Occupational Specialty, or MOS) training to prepare them for service in the Marine Corps at large (Fleet Marine Force or other operating forces assignments). The majority of Marine Corps officers are commissioned through the USMC Officer Candidate School (OCS), but many are also graduates of the U.S. Naval Academy, or other service academies who choose to commission with the Marine Corps instead. Restricted Line/Limited Duty Officers are direct commissioned from the chief warrant officer ranks as either a first lieutenant or captain and do not attend BOC; however, as warrant officers, they have already completed the WOBC at TBS prior to beginning their officer service in the operating forces. Most officers attend BOC as a second lieutenant immediately after commissioning at OCS or within a few months of graduation and commissioning from either the USNA or an NROTC program. Some newly commissioned officers may serve a short period of time in an interim assignment (such as an assistant athletic coach at the USNA) before beginning TBS/BOC. A few officers attend BOC as a first lieutenant because they were commissioned through the Platoon Leaders Class (PLC Law) program, which permits them to attend law school as second lieutenants and then attend TBS/BOC after promotion to first lieutenant upon receiving their law degree. In very rare cases, an officer who receives an initial commission in another branch of the US armed forces, and who has already been promoted to first lieutenant, may receive an interservice transfer to the Marine Corps and attend TBS as a first lieutenant. Course overview The Officer Basic Course currently lasts 28 weeks, during which new officers receive classroom, field, and practical application training on weapons, tactics, leadership and protocol. The course is split into three graded categories:, Leadership, Academics, and Military Skills. Much like OCS, graded events are split between events that are graded and events that must be passed. Events that must be passed are the 15-mile hike, all three exams, the Endurance Course, Final Land Navigation, Night Land Navigation, and Rifle and Pistol Qualification. Events that simply are n a grade are the 3, 6, 9, and 12 mile hikes, leadership billets in field exercises, and various decision-making exercises. Classroom