The Marine Commanding Officer is responsible for all the Marine personnel assigned to the ship or facility. He or she is in required to take command of any special ground operations and lease such actions with security. The Marines could be called the 24th century commandos.
The CO can range from a Second Lieutenant on a small ship to a Lieutenant Colonel on a large facility or colony. Charged with the training, condition and tactical leadership of the Marine compliment, they are a member of the senior staff.