Why do the French "Commandos Marine" wear their berets with the cap-badge on the left?

The "Commandos Marine" are the Special Operation Forces of the French Navy. The "Commandos Marine" are nicknamed "Bérets Verts" (Green Berets). They operate under the Naval Riflemen and Special Operations Forces Command and form part of the French Special Operations Command. The "Commandos Marine" were formed in 1942 during World War II in the United Kingdom and were modelled on the British Commandos (who were founded in 1940). They were formed from Free French volunteers from different services, mainly from Navy "Fusiliers Marins" (Naval Infantry), other navy specialities and even from the army.

They were trained at the Commando Training Centre in Achnacarry, Scotland and joined No. 10 (Inter-Allied) Commando as the 1st and the 8th Troops. The 1st “Bataillon de Fusiliers Marins Commandos” (Commando Naval Riflemen Battalion) took part in the Normandy Landing on D-Day under the command of Lieutenant Commander Philippe Kieffer (pictured), on Sword Beach, and were for the occasion integrated in No. 4 Commando. They further participated in the Netherlands campaign, still associated with No. 4 Commando. When the British Commando Units were disbanded at the conclusion of World War II, the two French Troops were repatriated to France.

To commemorate their British Commando origins, the beret of the French naval commandos is worn British style, pulled to the right with the badge worn over the left eye or temple, the opposite of all other French military units.