Naval rating

In a military navy, a rate or rating, and sometimes known as a bluejacket in the United States, is a junior enlisted sailor who is below the military rank of warrant officer. They are not a commissioned officer. Depending on the country and navy that uses it, the exact term and the range of ranks that it refers to may vary.

Royal Navy
In the Royal Navy (RN) and other navies in the Commonwealth, rate and rating are interchangeably used to refer to an enlisted sailor who is ranked below warrant officers and commissioned officers, but may include petty officers and chief petty officers. Specifically, rate is the term used to describe generically all members of all ranks below a warrant officer; whereas rating is part of the official name of individual specific ranks, such as Able Rating and Leading Rating.

The term comes from the general nautical usage of 'rating', to refer to a seaman's class or grade as recorded in the ship's books. The system of conferring authority on sailors in the Royal Navy evolved through the recognition of competence: landsman, ordinary seaman, able seaman, through to the appointment of authority as a petty officer.

The general structure for ratings in the Royal Navy now used breaks down into four major groupings:
 * Able Rating (OR-2)
 * Leading Rating (OR-4)
 * Petty Officer (OR-5/OR-6)
 * Chief Petty Officer (OR-7)

United States Navy & United States Coast Guard
In the United States Navy (USN), the term bluejacket is used instead to refer to enlisted sailors that rank below a chief petty officer. 'Bluejacket' derives itself from an item of clothing that was worn by junior enlisted sailors before 1886. It was used especially when the sailors were deployed ashore as infantry.

In the United States Navy and United States Coast Guard, the term rate refers to an enlisted member's pay grade (i.e. relative seniority or rank), while rating refers to occupational field. In the U.S. Navy and Coast Guard, an enlisted sailor is most commonly addressed, both verbally and in correspondence, by a combination of their rate and rating rather than by rate alone, unlike in other branches of the armed forces. For example, a sailor whose rate is 'Petty Officer 1st Class' (pay grade E-6) and whose rating is 'boatswain's mate' would be addressed as 'Boatswain's Mate 1st Class' (abbreviated BM1). However, it is also correct to address sailors in pay grades E-4 through E-6 simply as 'petty officer' (e.g. 'Petty Officer Jane Smith') and pay grades E-7, E-8, and E-9 are addressed as 'Chief', 'Senior Chief', or 'Master Chief' respectively. Pay grades E-3 and below maybe referred to as their rate and rating, a Gunner's Mate Seaman Apprentice would be 'GMSA'. Those who do not have a rating, are sometimes referred to as 'non-rates', and simply addressed as 'Seaman', or by their last name alone; i.e. 'Seaman Jones' or merely 'Jones'.