This is a list of sixth rate, corvette and sloop classes of the Royal Navy. In the Age of Sail ships were divided into six ranks in 1626 to govern pay rates for officers in 1626. Until the 1840s when steam power was being introduced this system was in place, The vessels classed as six rates were used in trade protection and at times could be used as scouts for the fleet (a task normally associated with Fifth rates). The rules governing the classification of Six rates would change until the mid 18th Century when it was formally established based on ship size armament and crew size. In 1626 a sixth rate was categorized as a ship having a crew size of 40 to 50 men. In 1653 the was changed to at least 40 up to a maximum of 79 men. By the end of the 1600s crew size had grown to over 100 men wit