Navigation and Seamanship

4.3.3.2. Types of buoys

7. Whistle buoy: These are similar to bell buoys except they carry a whistle sounded by the sea’s motion or horns that are sounded at regular intervals by mechanical or electrical means.

A buoy generally similar in construction to a bell or gong buoy but which has a low-pitched whistle signal that is activated by the rise and fall of the buoy in a seaway. A horn buoy is must the same except that its sound signal is electrically powered by batteries within the lower part of the buoy.

8. Combination Buoys: These are buoys in which a light and sound signal are combined, such as a lighted bell, gong, or whistle buoy. Combination buoy, A buoy having a light signal and sound signal, such as a lighted bell buoy, a lighted gong buoy, etc. The overall shape and general physical characteristics of these buoys may be seen in fig.507.

9.Station buoys : Buoys do not always maintain exact positions; therefore, they should always be regarded as warnings and not as fixed navigational marks, especially during the winter months or when moored in exposed waters. A smaller nun or can buoy called a station buoy, is sometimes placed in close proximity to a major aid, such as a sea buoy, to mark the station in case the regular aid is accidentally shifted from station. Station buoys are colored and numbered the same as the major aid to navigation. Lightship station buoys bear the letters “LS” above the initials of the station.

Unlighted buoys and day beacons are marked with reflective tape. This greatly facilitates locating the buoys at night with a searchlight. Reflective areas may be red, green, white, or yellow, and have the same significance as lights of these colours.