In recognition of the many responsibilities that fall upon those who successfully command (or have successfully commanded) deploying, afloat, or operational units classified as sea-going commands that fall under the operating forces of the U.S. Navy and Marine Corps, the Command at Sea insignia is authorized for wear by selected unrestricted line (URL) officers in the grade of captain and junior.
The insignia may be worn as soon as the officer assumes command and upon successful completion of a sea tour (this must be at least six months), and it may be worn in accordance with the guidelines set forth in the United States Navy Uniform Regulations. Flag officers who were earned this insignia while they were serving at the rank of captain or junior are allowed to continue wearing it if they so desire (again in accordance with uniform regulations).
While all commands are obviously important, some of them do not confer eligibility for the Command at Sea badge. Here is a list of the general categories that qualify, but be aware there are sometimes exceptions and exclusions (these can be found in MILSPERMAN 1210-170, Command at Sea Insignia: Qualifications).
Commissioned surface ships (excluding floating dry-docks)
All ship and submarine divisions, squadrons, and groups
Aviation squadrons and wing commanders including (excluding several types of training, test, and evaluation units)
Coastal and riverine squadrons and groups, assault craft units, beach master units, and naval beach units and groups.
Special warfare teams, units, squadrons, and support activities and groups.
Explosive ordnance disposal units and groups.
Space shuttle/space station mission commanders.
All commanding officers of surface ship and submarine pre-commissioning units.
Those specifically ineligible to wear the Command at Sea insignia include Restricted Line and Staff Corps officers; officers who, without orders from Navy Personnel Command, temporarily succeeded to command during the absence of the Commanding Officer; officers removed from command for cause; officers assigned to billets designated “officer in charge,” or whose previous billets were re-designated “Commanding Officer” subsequent to their detachment; and inactive reservists who have been assigned as “prospective commanding officer” a Navy Reserve training vessel or crew.
The six stars at the top of the insignia are symbolic of the first six vessels of the United States Navy, which were launched over a period lasting from 1797 to 1800. They include the USS United States, USS Constellation, USS Constitution, USS Chesapeake, USS Congress, and USS President.