M23 exchanged its original 9.2-inch battery for a 7.5-inch gun and increasingly strong anti-aircraft armament. After Dover Patrol duty it joined the North Russian Expeditionary Force and did not return to Britain until November 1919. Conversion into a Royal Naval Volunteer Reserve drill ship gave the small monitor an institutional role far beyond its emergency wartime purpose. Renamed Claverhouse, it remained in reserve training service until 1959.
Notable Point · 29:44-32:05
M23's journey from expeditionary monitor to reserve drill ship
M23's repeated rearmament and survival as an RNVR drill ship until 1959 show how a disposable wartime monitor acquired a four-decade training afterlife.