The Echo-class was a class of inshore survey vessel built for the British Royal Navy in 1958–1959. The class was designed to operate in close waters such as harbour approaches, shipping lanes, rivers and estuaries. Together, the ships of this class formed the Royal Navy's Inshore Survey Squadron. In the late 1960s, two Ham-class minesweepers, HMS Powderham and Yaxham were rebuilt as inshore survey vessels very similar to the Echos, although they could be identified by having an enclosed wheelhouse and a tripod mast. They were renamed HMS Waterwitch and Woodlark, respectively.