Glossary - Part G

•  Gallery: On a lighthouse tower, a platform or walkway or balcony located outside the watch room (main gallery) and/or lantern room (lantern gallery).

•  Geographic Range: The greatest distance the curvature of the earth permits an object of a given height to be seen from a particular height of eye without regard to luminous intensity or visibility conditions.

•  Gong: A wave actuated sound signal on buoys, which uses a group of saucer-shaped bells to produce different tones.

•  Group Flashing Light: A flashing light in which a group of flashes is regularly repeated.

•  Group-Occulting Light: An occulting light in which a group of eclipses, specified in number, is regularly repeated.

•  Guide Rollers: Wheels that are positioned, on rotating lens assemblies, to keep the lens assembly centered around the vertical axis of the lens, as it rotates.