Captain (Navy)
From Halopedia, the Halo wiki
Captain is a rank of the Commissioned officers group. It is between commander and Rear Admiral (Lower) and is equivalent to Marine a Colonel.
They command an entire ship, battle group, or a small fleet unless an Admiral of any kind is present.
A captain also may be referred to as the Skipper as heard in the Pillar of Autumn (Level) in halo 1
