This is a Royal Marines training photo most likely taken at the RM Infantry Training Centre at Lympstone. Photo courtesy of Dale Wright who adds, "My Grandfather Sidney Edwards is top left back row. He became a Corporal. He was 36/37 when he joined the RM Commandos. My Grandfathers service number was CH/X 104698. He wrote many letters both from England and in France. In England, many of them were addressed, 'HQ 1st Special Service' in Petworth Sussex. From my research, I am pretty sure that the only RM Commando unit attached to this was 45."