[PUBLICATIONS SUPPLEMENTING NAUTICAL CHARTS.]
There are several publications in book and in chart form which are either necessary or convenient for use in connection with nautical charts. These comprise the coast pilots, notices to mariners, tide tables, light and buoy lists, and various special charts.
Coast pilots, or sailing directions, are books giving descriptions of the main features, as far as of interest to seamen, of the coast and adjacent waters, with directions for navigation. They contain much miscellaneous information of value to the mariner, especially the stranger. Although they contain additional facts which cannot be shown on the charts, they are not at all intended to supersede the latter; the mariner should in general rely on the charts. The sailing directions can be less readily corrected than the charts, and in all cases where they differ the charts are to be taken as the guide.
The most extensive series of sailing directions is that published by the British Admiralty, comprising fifty-six volumes and including all the navigable regions of the world. In the United States the Coast and Geodetic Survey publishes ten volumes of coast pilots for the Atlantic, Gulf, and Pacific coasts, Porto Rico, and southeastern Alaska, and eight volumes of sailing directions for Alaska and the Philippine Islands. The United States Hydrographic Office publishes sixteen volumes of sailing directions for various parts of the world.
Notices to Mariners are published at frequent intervals, giving all important corrections, which should be at once applied by hand to the charts, such as rocks or shoals discovered and lights and buoys established or moved. New charts, new editions, and canceled charts are also announced.
These notices should be carefully examined and the necessary corrections made on all charts of the sets in use on the vessel. A chart should be considered as a growing rather than a finished instrument, and constant watchfulness is required to see that it is kept up to date. Neglect of this may cause shipwreck, as the following instance shows. Report came to Manila in 1904 that there was a low sand islet lying off the very poorly charted northeast coast of Samar; this information was promptly published in the local Notice to Mariners. About a month later a small steamer was sent to land some native constabulary on that coast. The captain failed to obtain or observe this notice, and approached the coast before daylight on a course which led directly across the sand islet. The vessel was driven far up on the sand, where it still lies.
In the United States, weekly Notices to Mariners are published by the Department of Commerce and Labor for the coasts under the jurisdiction of the United States, and by the Navy Department for all regions. These notices are distributed free and can be obtained from chart agents and consular officers. In Great Britain the notices are published at frequent intervals by the Hydrographic Office, and practically all countries issuing charts also issue such notices. Information as to important changes in lights and other announcements of navigational interest are also sometimes printed in the marine columns of newspapers and in nautical periodicals.
Tide Tables. Brief information as to the time and height of the tide is usually for convenience given on the face of the chart. More complete information is published in the Tide Tables, with which every navigator should be provided. "The Tide Tables for United States and foreign ports," published annually in advance by the United States Coast and Geodetic Survey, give complete predictions of the time and height of high and low water for each day of the year for 70 of the principal ports of the world, and the tidal differences from some principal port for 3000 subordinate ports. The other leading nations also publish annual tide tables; those of the British government are entitled "Tide Tables for British and Irish ports, and also the times of high water for the principal places on the globe."
Light and buoy lists. Brief information as to all artificial aids to navigation is shown on the charts. Every vessel should also have on board the latest official light and buoy lists, which give a more detailed description than can be placed on the charts.
Light and buoy lists for the coasts of the United States are published annually by the Light-House Board. The United States Hydrographic Office publishes a "List of Lights of the World" (excepting the United States), in three volumes.