Navigation and Seamanship

4.3.3.1. Types of buoys

4. Lighted buoy: These carry batteries or gas tanks and are surmounted by a framework supporting a light. A description of the lights on lighted buoys is given later. A steel float on which is mounted a shor steleton tower at the top of which a light is placed. A set of electric batteries (or other sources of power) which operate the light, is placed in the body of the buoy.

5. Bell buoy: t hese have flat tops, surmounted by a framework supporting a bell. Older bell buoys are sounded by the motion of the sea. Newer types are operated automatically by compressed gas or electricity. A steel float topped with a short skeleton tower in which there is a bell fixed with several clappers-usually four- hung externally so that they will strike the bell as it rocks with the motion of the sea. A few shore stations and fixed aids to navigation have bells that are sounded by mechanical means, but at most locations these have been replaced by electrically operated horns.

6. Gong buoy: These are similar to bell buoys except that they have a series of gongs, each with a different tone. Generally similar in construction to a bell buoy except that rather than a bell it has several, usually four, gongs mounted in a vertical stack, each of which sounds a different note; each gong has its own clapper of a length so as to strike only that going.