User:James T. Kolk/Rank Indices/Vulcan High Command Rank Index: Officer
Officer Ranks
Captain
Captains are the most senior of line officers. Captains most often command Starships or Starbases of medium to large size. Captains may also command planetary outposts or serve as division heads for the Starfleet Bases on major worlds.
Subcommander
Commanders are senior line officers. Commanders usually serve as the Executive Officer, Operations Officer, or Security Chief onboard a starship. Commanders may command small starships of under 100 crewmen, but this is rare. Commanders may also command small Starbases or minor outposts. Taking the Bridge Officer's Test is the only way for a science or medical officer to be promoted to Commander, pending completion of the other requirements
Altern
Lieutenant Commanders are senior line officers. Lieutenant Commanders usually serve as department heads aboard starship or on large Starbases. Lieutenant Commanders may be the executive officers on starships with a crew of less than 250, but usually Commanders fill that role.
Subaltern
Lieutenants are the most common Commissioned Officers. Lieutenants can perform almost any Officer duty on a starship, save for being the Commanding or Executive Officer. In some cases Lieutenants can even be department heads, especially on smaller starships.
Lieutenant
Lieutenants Junior Grade are junior Commissioned Officers. Lieutenants Junior Grade may be the Medical Officer or Science Officer on a mid to large space station, or man a Bridge Station. Officers typically spend around 2 years as a Lieutenant Junior Grade.
Sublieutenant
Ensigns are the most junior of Commissioned Officers. Ensigns often serve as Flight Controller aboard starships, or Operations Officer on small Starships. Ensigns can also serve in relief or assistant capacities to most other positions aboard ship. It is rare, but not unheard of, for a Cadet at Starfleet Academy to be granted a temporary Commission of Ensign. This is only done in cases of truly outstanding grades. Officers typically spend around 3 years as an Ensign.