Chief petty officer


 * You may also be looking for senior chief petty officer, master chief petty officer, Command Master Chief Petty Officer, Fleet Master Chief Petty Officer or Master Chief Petty Officer of Starfleet.

Chief petty officer is the highest enlisted rating in Starfleet. The chief petty officer, invariably referred to as chief, was a senior non-commissioned officer and is often in control of an entire section of petty officers and unrated enlisted personnel.
 * The term "chief petty officer" is deduced from real-world naval nomenclature; it is not used in canon Trek, only the word "chief".

Chiefs are further subdivided into a series of ranks based on seniority and merit. These ranks, from lower to higher are as follows: chief, senior chief, and master chief.

A chief or senior chief is addressed as Chief (with surname, as in Chief O'Brien in the first instance, and as plain Chief thereafter). A master chief is addressed as Master Chief.

While chiefs are subordinate to all commissioned officers, intelligent ensigns or lieutenants will listen to their chiefs, as these non-commissioned officers frequently have far greater experience than the junior officers under whom they serve. Even senior officers recognize the value of a good chief petty officer and will take their suggestions and advice seriously.

Chief of the boat
Usually, the most senior chief on board ship is designated the Chief of the Boat. In many ways, the Chief of the Boat serves as the enlisted counterpart to the ship's first officer. His responsibilities include ensuring that the other chiefs and the duty sections they are responsible for are properly carrying out their duties, carrying out crew evaluations of enlisted personnel, handling minor disciplinary infractions that do not require the first officer or captain's direct attention, and otherwise liaising with the captain and first officer to ensure the smooth running of the ship. (Star Trek: Dauntless, Star Trek: Independence,, Star Trek: Tales of the USS Bluefin, et al.)

History
The term "chief petty officer" and "Chief of the Boat" originate in the maritime navies of Earth. The abbreviation in the United States Navy is CPO.

The navy rank system was adapted and simplified for use in Starfleet. In the 23rd century complex and safety-critical systems like the transporters are only operated by chiefs or senior engineering officers. (TOS)

By the 24th century the rating of chief was subdivided in to chiefs, senior chiefs and master chiefs similarly to 20th century usage. (DS9)
 * We can deduce this from O'Brien's insignia, which indicates senior chief. The distinction is not articulated in dialog. Previous costumes did not have distinct insignia for subdivisions of chief, but they have been created speculatively for RPGs.

Starfleet insignia

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