2012 U.S. Naval Observatory Nautical Almanac
The United Kingdom Hydrographic Office & U.S. Naval Observatoryare responsible for this text. The United Kingdom Hydrographic Office is a part of the UK Ministry of Defense and supplies the Royal Navy and international mariners with nautical charts and publications. The U.S. Naval Observatory produces information on positioning, navigation, and timing, and reports to the U.S. Navy and U.S. Department of Defense.