Discover our Royal Navy M Class Submarines photo prints, featuring some of the most unusual submarines ever built. Ordered as K Class boats and redesigned as submarine monitors, they each carried a single 12 inch gun taken from the old Formidable Class battleships, mounted forward of the conning tower and able to be fired from periscope depth. Three boats were completed; the war ended before any saw action, and M2 was later converted to carry a seaplane and M3 to lay mines. HMS M1 was lost with all hands off Start Point in November 1925 after a collision with the Swedish steamer Vidar. Available as high-quality photo prints or premium framed prints, they are perfect for collectors and enthusiasts of Royal Navy history. Browse the collection to find the ideal print for your home or office.