Muster roll from Murmansk, on the return trip following the Northern Russia Expedition. Note that there are several crewmen with the rank CMM. The crewmen for this expedition were volunteers from among the chaser men returning from ASW operations. As the journey to the White Sea was a significant undertaking with great demands on the engineering crew, it is unsurprising that crewmen with greater training and experience in engineering were selected.
National Archives, Washington, D.C.