There are two Command insignia: Command at Sea and Command Ashore/Project Manager. Both are a command military badge of the United States Navy.
Either is worn centered over the right pocket while the wearer is holding an active command at sea billet as an incumbent, and is worn centered on the upper portion of the left pocket flap, under the warfare insignia and ribbons, after completion of the command tour.
A post tour officer wears the insignia on the left breast 1/4 inch below the top of the pocket/flap. If a warfare or qualification insignia is already occupying that position, it is then worn 1/4 inch below that insignia, or on uniforms with pocket flaps, 1/4 inch below the flap. Women in full dress will wear post tour command insignia 1/4 inch above the left pocket, medals or primary breast insignia. Men in full dress will wear their post-tour insignia below the bottom row of medals, or below their second qualification or warfare badge if they have one. Only one post-tour command insignia may be worn.
Prior to late 2015, U.S. Navy officers previously awarded the Command at Sea pin, upon promotion to rear admiral, lower half (O-7), were not allowed to wear them afterwards. In 2015, wear by U.S. Navy flag officers was authorized, but only in the post-tour position, below the ribbon bars. Therefore, even if an admiral is holding an operational command, they are only authorized to wear the badge in the post-completion position on the pocket flap.
The Command at Sea insignia was established in the U.S. Navy in 1960 and is for commissioned officers between the ranks of lieutenant (O-3) and captain (O-6) who are in or have been in command of a commissioned warship or submarine, an operational fleet air unit, or a SEAL command at the O-5 or O-6 level.
The Command Ashore/Project Manager insignia, designates senior officers who are in command of, or have previously commanded, a ship, submarine, operational/deployable fleet air unit in naval aviation, or a special warfare (SEAL) unit. This includes those in charge of a major program or project (the latter being primarily in the Naval Air Systems Command or Naval Sea Systems Command).