M27's armament moved from the standard 9.2-inch fit through six-inch and finally four-inch weapons as its duties changed, before it was scuttled in Northern Russia. The unusually varied fit illustrates how a monitor could be rebuilt around whatever guns its next assignment required. M28 spent most of its career in the Aegean, including coastal bombardment of a Bulgarian port in October 1915. It was trapped with Raglan at Kusu Bay in 1918. Against the former Goeben and Breslau, a small monitor's close-support battery had no realistic answer.
Notable Point · 36:23-39:12
M27's evolving armament and M28 at Imbros
M27 and M28 show the M15 class changing weapons for river war while remaining vulnerable to larger surface combatants.