The Mariner class was a class of six 8-gun gunvessels (sloops from 1884) built for the Royal Navy between 1883 and 1888. Four were built in the Naval Dockard at Devonport, and two elsewhere; the Acorn was built by contract at Jacobs Pill on the Pembroke River (a private yard founded in the 1870s by Sir Edward Reed), while the Melita was built in the Malta Dockyard, the only substantial ship of the Royal Navy ever to be built in the island.