When war came to Europe in 1939, Ireland needed boats to protect her waters and her neutrality. With the establishment of Marine and Coastwatching Service in September 1939, six motor torpedo boats were purchased by the Irish Government from the British.
The Torpedo boats were numbered ‘M1’ to ‘M6’. All six boats were built by Thornycraft at Hampton on the Thames in England. M1 had originally been built for the Estonian Navy and M2 for the Latvian Navy but were not delivered as both countries had fallen under the Soviet sphere of influence under the provisions of the 1939 Molotov–Ribbentrop Pact with Nazi Germany.
Ireland took delivery of the first boat in Jan 1940. The signing over of the M2 was delayed due to the mass evacuation of British troops from Dunkirk. The story goes that the M2 was operated by Thornycraft personnel with a volunteer Irish naval crew on board and played a role in Operation dynamo assisting in the evacuation of troops. M2 eventually arrived in Cobh in the June and M3 arrived in August.
The first three boats were 22 metres long and had petrol engines. With 2300 horse power they could achieve a max speed of 40 knots. The last three boats were larger and heavier and were each equipped with a 20 mm Madsen machine gun.
The boats functioned mainly in a patrolling role during the war, regulating merchant ships and protecting fisheries. They were also used to place defensive sea mines. In the footage above, the M1 boats can be briefly seen in action off Dun Laoghaire.
By 1941 the Marine and Coastwatching Service consisted of 10 craft (6 motor torpedo boats plus 4 assorted vessels) and about 300 active personnel. In 1942 the Service was renamed the Marine Service. It was in 1946 the Irish Naval Service as we now know it was formed.