"To provide medium and light fire support to land units close to the coastlines, the Royal Navy constructed a class of 14 small monitors fitted with reserve guns for obsolete armoured cruisers. Four of these are in service close to home, three of which are armed with 7.5\" guns, while one (M27) has only a 6\" gun."@en . . . . "M15 class"@en . "To provide medium and light fire support to land units close to the coastlines, the Royal Navy constructed a class of 14 small monitors fitted with reserve guns for obsolete armoured cruisers. Four of these are in service close to home, three of which are armed with 7.5\" guns, while one (M27) has only a 6\" gun."@en .