The islands cluster round the huge deep-water anchorage of Scapa Flow like a protecting hand, and in both World War I and World War II, the Royal Navy had a major base there, enabling them to challenge any attempt by German warships to emerge into the ocean through the Norwegian Sea. After the Armistice in 1918, the German High Seas Fleet was transferred in its entirety to Scapa Flow while a decision was to be made on its future; however, the German sailors opened their sea-cocks and scuttled all the ships. Most ships were salvaged, but the remaining wrecks are now a favoured haunt of recreational divers.