Signalman 1 & C - Historic Naval Ships Association

periodical announces new nautical charts andpublications, new editions, cancellations, and changesto nautical charts and publications. It also summarizesevents of the week as they affect shipping, advisemariners of special warning or items of generalmaritime interest, and includes selected accounts ofunusual phenomena observed at sea. Distribution ofNotices to Mariners is made weekly to all U.S. Navyand Coast Guard ships and to most ships of themerchant marines.The classified chart and publication correctionsystem is based on Classified Notices to Mariners,published on an as-needed basis by the DMAHTC toinform mariners of corrections to classified nauticalcharts and publications.HAND CORRECTIONSCorrections on charts in writing should be keptclear of water areas as much as possible unless theobjects referred to are on the water. When you areinserting written corrections, be careful not toobliterate any of the other information already on thechart.When cautionary, tidal, and other such notes areto be inserted, they should be written in a convenientbut conspicuous place where they will not interferewith any other details.The year and number of each Notices to Marinersfrom which corrections have been made are to beentered in ink at the lower left corner of the chart.Temporary changes should be made in pencil. Formore information on chart corrections, visit your localQuartermaster.AIDS TO NAVIGATIONLEARNING OBJECTIVES: Identify andexplain the aids to navigation, including lights,lighthouses, buoys, daybeacons, ranges, andfog signals.In piloting, a ship's position is determined bybearings or ranges of objects whose exact locationis shown on the area chart. Such objects are aids tonavigation, and may be natural or man-made.Examples of natural objects are prominent hills,rocks, and mountains. Man-made objects includebuildings, TV towers, and smokestacks that arecoincidentally located where they can be ofassistance to a navigator.Aids to navigation are lighthouses, lightships,minor lights, buoys, and daybeacons. Aids are placedso that, insofar as possible, they provide a continuousand unbroken chain of charted marks for coast andchannel piloting. Most harbors and some coasts arewell marked with man-made aids to navigation, yet noattempt has ever been made to mark every mile of theworld's coastline. Such marking would be impracticalbecause many regions are seldom navigated. In someareas, the lack of artificial aids makes it necessary touse landmarks.LIGHTSA ship cannot suspend piloting operations whendarkness falls and daytime navigational aids no longercan be seen. For this reason, aids to navigation arelighted whenever it is necessary. For purposes ofidentification, lights have individual characteristicsregarding color, intensity, and system of operation.Some of a light’s characteristics may be printed nearits symbol on the chart. Detailed information,including the height—which, combined with intensityand observer's height, determines the light'svisibility—is set forth in either List of Lights or LightLists.The DMAHTC publishes seven volumes of Listof Lights. The volumes are divided geographically,but exclude the United States and its possessions.This list contains a description of lighted aids tonavigation (except harbor-lighted buoys) and fogsignals. Storm signals, signal stations, radiodirection finders, and radio beacons located at ornear lights are also mentioned in this list.Lights located in the United States and itspossessions are described in Light Lists, published bythe U.S. Coast Guard.LIGHT CHARACTERISTICSWhite, red, green, and yellow are the fourstandard colors for lights on aids to navigation. Thesignificance of the different colors is importantchiefly with regard to channel buoys; thissignificance is discussed later in the sections dealingwith buoys.Some navigational lights are fixed, meaning theyburn steadily. The most important lights, however, gothrough repeated periods of systematic changes oflight and darkness. Those characteristics of anavigational light are the most valuable for9-7