The guns used by the M boats came from the Majestic Class battleships - the guns and mounting weighting about 120 tons and the 40 rounds of ammunition 29 tons.
At the end of the war, the question of future employment of the M Class arose as 'there were no targets and the enemy had not initiated anything bold in submarine policy'. Consequently, during the 1920s, the three M Class submarines led contrasting lives.
On October 25th, 1925, M1 was rammed by the SS Vidal off Start Point and was lost without survivors.
