RMS Mauretania (1906) launched by the Duchess of Roxburghe. At the time of her launch, she was the largest moving structure ever built, and slightly larger in gross tonnage than "Lusitania". The main visual differences between "Mauretania" and "Lusitania" were that "Mauretania" was five feet longer and had different vents. "Mauretania" also had two extra stages of turbine blades in her forward turbines, making her slightly faster than "Lusitania". "Mauretania" and "Lusitania" were the only ships with direct-drive steam turbines to hold the Blue Riband; in later ships, reduction-geared turbines were mainly used. "Mauretania"s usage of the steam turbine was the largest application
German submarine U-764 the war. In eight patrols she sank one merchant ship, for a total of , and 2 warships sunk (1,696 tons). "U-764" took part in eight wolfpacks, namely "U-764" surrendered on 14 May 1945 at Loch Eriboll, Scotland. She was sunk as a target in position as part of Operation Deadlight on 2 February 1946. German submarine U-764 German submarine "U-764" was a Type VIIC U-boat built for Nazi Germany's "Kriegsmarine" for service during World War II. She was laid down on 1 February 1941 by Kriegsmarinewerft Wilhelmshaven as yard number 147, launched on 13 March 1943 and commissioned on