sloops were small warships intended for colonial "gunboat diplomacy" deployments, surveying duties, and acting during wartime as convoy escorts. As they were not intended to deploy with the fleet, sloops had a maximum speed of less than . A number of such sloops, for example the and classes, were built in the interwar years. Fleet minesweepers such as the were rated as "minesweeping sloops". The Royal Navy officially dropped the term "sloop" in 1937, although the term remained in widespread and general use. World War II During World War II, 37 ships of the were built for convoy escort duties. However, the warship-standards construction and sophisticated armaments of the sloop of that time did not lend themselves to mass production, and the sloop was supplanted by the corvette, and later the frigate, as the primary escort vessel of the Royal Navy. Built to mercantile standards and with (initially) simple armaments, these vessels, notably the and classes, were produced in large numbers for the Battle of the Atlantic. In 1948 the Royal Navy reclassified its remaining sloops and corvettes as frigates, even though the term sloop had been officially defunct for nine years. 2010s The Royal Navy has proposed a concept, known as the "Future Black Swan-class Sloop-of-war", as an alternative to the Global Corvette of the Global Combat Ship programme. Notable sloops Perhaps the most famous sloop was , in which Captain James Cook made his second and third Pacific voyages. This was not a purpose-built naval sloop, but was a former merchant collier purchased by the Royal Navy and adapted for exploration purposes. Cook called Resolution "the ship of my choice", and "the fittest for service of any I have seen". , a sloop of the Continental Navy which served on diplomatic missions to France. Independence was the first ship acquired by the Continental Congress for use during the American Revolutionary War. She captured two British prizes during her cruises to Europe. In 1780, , a sloop bearing 16 six-pounders and a crew of 99 seamen delivered Major John Andre to his meeting with General Benedict Arnold, near Haverstraw, New York, to finalise plans for Arnold's surrender of West Point to the British. After Andre's capture and the unmasking of the plot, Arnold fled to British lines, borne down the Hudson River aboard Vulture. , a Cherokee-class brig-sloop re-rigged as a three-masted barque, is famous as the ship Charles