Watchstanding regulate the sailors' duty watches and for other purposes (see main article). Unlike civil clock bells, the strikes of a ship's bell do not accord to the number of the hour. Instead, there are eight bells, one for each half-hour of a four-hour watch. Bells would be struck every half-hour, and in a pattern of pairs for easier counting, with any odd bells at the end of the sequence. Watchstanding Watchstanding, or watchkeeping, in nautical terms concerns the division of qualified personnel to operate a ship continuously. On a typical seafaring vessel, be it naval or merchant, personnel keep watch
The Nautical Almanac The Nautical Almanac The Nautical Almanac has been the familiar name for a series of official British almanacs published under various titles since the first issue of "The Nautical Almanac and Astronomical Ephemeris", for 1767: this was the first nautical almanac to contain data dedicated to the convenient determination of longitude at sea. It was originally published from the Royal Greenwich Observatory in England. A detailed account of how the publication was produced in its earliest years has been published by the National Maritime Museum. Since 1958 (with the issue for the year 1960), [[Her Majesty's Nautical Almanac Office]] and