Definition of Hms a3

She was a member of the first British A-class of submarines, although slightly bigger than the lead boat, HMS A1. She was built at Vickers, Barrow-in-Furness and was commissioned on July 13, 1904. She was accidentally rammed whilst surfacing by the submarine tender HMS Hazard off the Isle of Wight on February 2, 1912 and sunk with the loss of all on board. The wreck was salvaged and subsequently sunk as a gunnery target near Portland Bill on May 12, 1912 where she remains today.