U-boats. In 1917 alone, they sighted 175 U-boats and attacked 107. Because of the technology of the time the attacks were not very successful in terms of submarines sunk, but the sightings greatly assisted the Navy's surface fleets in combatting the enemy submarines. It was the RNAS which provided much of the mobile cover using armoured cars, during the withdrawal from Antwerp to the Yser, in 1914 (see RNAS Armoured Car Section below). Later in the war, squadrons of the RNAS were sent to France to directly support the RFC. The RNAS was also at one stage entrusted with the air defence of London. This led to its raids on airship stations in Germany, in places as far from the sea as the manufacturing site at Friedrichshafen. Before techniques were developed for taking off and landing on ships, the RNAS had to use seaplanes in order to operate at sea. Beginning with experiments on the old cruiser , special seaplane tenders were developed to support these aircraft. It was from these ships that a raid on Zeppelin bases at Cuxhaven, Nordholz Airbase and Wilhelmshaven was launched on Christmas Day of 1914. This was the first attack by British ship-borne aircraft; the first ship-borne aircraft raid was launched by the Japanese seaplane carrier Wakamiya on 6 September. A chain of coastal air stations was also constructed. This was followed with the Tondern raid, again against Zeppelins, which was the first instance of carrier launched aircraft. Notable personnel John Alcock – aviation pioneer Henry Allingham – mechanic – oldest man in the world from June to July 2009 and the last surviving member of the RNAS Richard Bell-Davies – 3 Squadron – awarded the Victoria Cross Noel Pemberton Billing – aviator, inventor, publisher and Member of Parliament. Norman Blackburn – aviation pioneer and joint managing director of Blackburn Aircraft Henry John Lawrence Botterell – Naval 8 – longest surviving First World War fighter pilot (he died 3 January 2003 at age 106) Frederick Bowhill – Squadron commander in Wing 2, later Commander-in-chief Transport Command RAF. Air Chief Marshal Arthur Roy Brown – Naval 9 – ace, officially credited with shooting down the Red Baron (although this is now generally discredited) Egbert Cadbury – credited with shooting down two Zeppelin over the North Sea Arnold Jacques Chadwick – DSC – Naval 4 ace on two types of aircraft: Sopwith Pup and Sopwith Camel