Norway's Directorate for Cultural Heritage has begun a unique program of setting up signs to highlight historical landmarks - underwater. About 30 shipwrecks in southern Norway will get the familiar preservation sign from the directorate, to help divers appreciate - and respect - some of the country's less obvious attractions. On Thursday the first sign, bearing the familiar pretzel-shaped landmark logo, will go up near a shipwreck in Vest-Agder County in southern Norway. The signs are built of acid-resistant steel and titanium to resist saltwater and other sea problems. Signs will be placed at depths of 10-30 meters (33-98 feet),...