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4.3.11. Day Beacons
DAY BEACONS In shallow waters, day beacons are often used instead of buoys, because they are less expensive to maintain. Normally , day beacons are unlighted. These are single piles or multiple-pile structures(dolphins) driven into to bottom, on which are placed one or more signboards called “daymarks” which convey information through their color, shape, and lettering or numbers. Day beacons, like lighthouses and light structures, usually are colored to distinguish them from their surroundings and make them easy to identify Day marks normally have reflective material as part of their design. Two such day beacons are in line, used for taking transit bearing from a vessel poisoned in a particular place. FOG SIGNALS Fog signals are audible signals used to locate a navigational aid when it is not visible due to unfavourable conditions like fog, snow, rain, smoke etc,. Generally, they are established with another form of aid such as buoy, lighthouse, light ships, etc,. Navigator will identify the location of the navigational aid by assessing the place from where the sound originates. The simple fog signals are bells, gongs or whistles on buoys. Radio and radar beacons: Like fog signals, radio beacons are also often co-located with other aids to navigation. At the conditions of restricted visibility and night hours these radio beacons are useful to take bearings from greater distances. Radar beacons, are also known as racons and ramarks. |