The Naval Long Service and Good Conduct Medal (1830) was introduced on 20 November 1830 and ratified by King William IV on 24 August 1831.

This medal, known as the "anchor type", could only be awarded to selected other ranks, ratings or marines after altogether 21 years of service and good conduct.

Whilst the qualifying period was reduced in 1977 from eighteen to fifteen years service for the Army and RAF, this reduction was not applicable for the Royal Navy.

[16] Any other rank, rating or marine who had completed fifteen years of reckonable service and who held three good conduct badges, became eligible to receive the medal.

Also from that date, an officer became eligible for the award of the clasp if at least twenty-two of the thirty years of his or her service had been in the ranks and provided that the conduct requirements had been met.

[1][2][16][20] This changed in October 2016 when officers who had not previously served in the ranks were also granted eligibility, providing their record was clear of disciplinary entries.

[21] In the order of wear prescribed by the British Central Chancery of the Orders of Knighthood, the Naval Long Service and Good Conduct Medal (1848) ranks on par with the Naval Long Service and Good Conduct Medal (1830) that it replaced.

Since the medal was instituted in 1848, seven obverse versions have been awarded, with two versions each during the reigns of Queen Victoria and King George V.[1][2] Reverse The reverse shows a starboard broadside view of HMS Victory, a three-masted ship of the line and Lord Nelson's flagship at the Battle of Trafalgar in 1805.

[25][1][2][26][16] The first version of the medal has the effigy of Queen Victoria on the obverse and was designed by William Wyon, the chief engraver at the Royal Mint from 1828 until his death.

The details of the recipient were either engraved or, after 1877, impressed around the edge of the medal,[27] showing his service number, rank and name and also the name of a Naval rating's ship or shore establishment, or a Marine's division.

The obverse has a raised rim, with the King's effigy in Admiral's uniform, facing left and inscribed "EDWARDVS VII REX IMPERATOR" around the perimeter.

The first version shows the King in Admiral's uniform, facing left and inscribed "GEORGIVS V BRITT: OMN: REX ET IND: IMP:" around the perimeter.

The initials "BM" on the truncation of the King's neck are those of the designer of the obverse, Bertram Mackennal, an Australian sculptor.

The effigy was designed by Mary Gillick and was also used on general-circulation coinage for the United Kingdom from 1953, as well as in cameo form on British commemorative postage stamps since 1966.

The medal will be awarded for any period of fifteen years service free of any disciplinary entries, regardless of rank.