from the use of the 12-inch gun than Germany. Why this was never thought of before construction remains a mystery. M2 and M3 were completed in 1920.
The fact that the M Class design got further than the conference table is a reflection of the failure by the Admiralty to recognize the proper nature of submarine operations. Although their 12-inch guns were ideally suited for bombarding coastal defences, their method of attack at sea was rather primitive. The attack procedure was to cruise at periscope depth until the target was 'lined up'. The submarine was then brought-up until about six feet of the gun barrel protruded from the water.
A round was fired and the submarine would then make a rapid dive - unable to fire again as the gun could not be reloaded
