HMS A8 was an early Royal Navy submarine.
She was a member of Group Two of the 1903 British A-class of submarines. Like the other members of her class, she was built at Vickers Barrow-in-Furness.
She sank with the loss of 15 crew as a result of an accident whilst running on the surface in Plymouth Sound on 8 June 1905. A sudden dip in the bow caused the submarine to be swamped through the hatch in the conning tower.Only 4 survived. She was salvaged four days after the accident at which point a loose rivet was found in the bow plating.[1] The submarine was then repaired and recommissioned and used for training during the First World War along with A9 as part of the First Submarine Flotilla, operating near Devonport through early 1916. She was scrapped in October 1920 at Dartmouth.
. Disasters of the Deep A Comprehensive Survey of Submarine Accidents & Disasters . Edwyn Gray . 2003. Leo Cooper. 0-85052-987-5 . 51–52 .