The Marine CO is responsible for all the Marine personnel assigned to the ship/facility. S/he is in required to take command of any special ground operations. The Marines could be called the Battlestar commandos. The CO can range from an Ensign 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. They are also in charge of all internal security of the ship. Answers to the Commanding Officer of the ship/facility.