High Quality Content by WIKIPEDIA articles! HMS Trafalgar is a decommissioned Trafalgar-class submarine of the Royal Navy. Unlike the rest of the Trafalgar-class boats that followed, she was not launched with a pump jet propulsion system, but with a conventional 7-bladed propeller. Trafalgar was the fifth vessel of the Royal Navy to bear the name, after the 1805 Battle of Trafalgar.