The Royal Canadian Navy was established in 1910 and modeled largely on the customs and traditions of the Royal Navy. Accordingly, on the 19th of June 1925 the tradition of recognition of 15 years of service, with a corresponding record of good conduct, by Petty Officers and men was instituted in the RCN. Recognition took the form of a medal of silver, which hangs from a straight clasp and bears on its obverse the effigy of the reigning Sovereign with the appropriate legend. The reverse depicts a ship of the line under sail encircled by a rope tied off at the bottom by a reef knot, around the outside of which is the inscription "FOR LONG SERVICE AND GOOD CONDUCT". Recipients who complete an additional fifteen years service under the same conditions as the original award are entitled to a clasp. Possessors of the clasp wear a rosette on the ribbon when it is worn alone.

In 1927 the first medals bearing the effigy of King George V in an admiral's uniform were issued to entitled men of the R.C.N. The medal continued to be issued to those eligible until it was superceded by the Canadian Forces Decoration (CD) which was introduced in 1950. Those who had service in the Naval Forces of Canada prior to the 10th of September,1939 were allowed to choose either the R.C.N. LS & GC or the CD. Those who were enrolled after the 10th of September 1939 were automatically awarded the CD at the appropriate time. However, the final issue of the Naval LS& GC did not occur until 1966. This was likely due to the recipient having enlisted prior to the cut-off date but having broken service.

A total of 864 medals were issued to the Royal Canadian Navy with three second award clasps. The medals were issued with seven different obverses as follows:

Up to 1966 a total of eight medals had been replaced due to loss or other causes and are not included in the totals given here.

Naming on the medals issued to Canadians was different from those issued to the Royal Navy. Medals of the R. N. carry the individuals number, rank, name, and ship. While those of the Royal Canadian Navy carry the man's rank, name and number, followed by the letters R.C.N. For some obscure reason the names of ships were not inscribed on Canadian medals.

The following are examples of medals with their exact naming as it appears on the medals.