Types of Buoys
Bell buoys have a flat top, surmounted by a skeleton steel framework
supporting a bell. The bell usually has four clappers, which strike the
bell as the buoy moves with the sea.
Gong buoys are similar to bell buoys except they have a series of gongs,
each with a different tone.
Figure 4-11. Can buoy on the left and nun buoy on the right.
Figure 4-12. Lighted buoy.