Officers in the Colonial Fleet are given ranks that are a fusion of those presently used in western armies and navies. Ronald D. Moore outlined the rank structure in a blog entry in February of 2005, stating that he wanted to keep the "co-mingled" ranks of the original series rather than reassign ranks based on real-world naval structure.
The Colonial Fleet commissioned officers are identified as:Admiral
- Vice Admiral
- Rear Admiral
- Junior Lieutenant
The ranks for enlisted crewmen are:Chief Petty Officer
- Petty Officer (first class)
- Petty Officer (second class)
The Colonial Marines have a different rank structure for enlisted men: Private, Corporal, Sergeant, etc. Their officer rank structure, if indeed one exists, has not been shown and it is unknown whether any commissioned Marine officers survived or if indeed the Colonial Marines had an officer corps.(Marines on the show have only been led by Fleet officers such as Apollo, Starbuck, Tigh, Athena or Sergeant Hadrian).
The command and executive officers of the Galactica are a Commander and Colonel, respectively, and have been since before the destruction of the colonies. Dr. Cottle holds the rank of Major, as did Lee Adama prior to his promotion to Commander (this is later reversed). There are a few senior officers with the rank of Captain as well as several lieutenants. The second season introduced Admiral Helena Cain (played by Michelle Forbes), in command of the Battlestar Pegasus (mentioned by Admiral Adama as being specifically a Rear Admiral at one point).
Recurring Marine characters include Galactica's Master-at-arms, Sergeant Hadrian, played by Jill Teed. The character, however, is never explicitly identified as a Marine. Another recurring Marine character is Corporal Venner, played by Chris Shields. In addition to these Marines, numerous Privates and at least two Gunnery Sergeants are known to exist (one appeared in the season 2 episode "Sacrifice" and another appeared in the season 3 episode "Exodus Part 1").
In addition, at least two Marines have been seen with two vertical, white bars painted on the backs of their helmets, similar to the symbol used for a Captain by the US Military.
Colonial Marine Insignia: