Lighthouses are the signal stations by means of which mariners determine their exact position. Mariners had once to be satisfied with natural landmarks, from which to obtain their bearings. These often being lacking at points where most needed, towers were built, and eventually lights were placed in many of them. The modern lighthouse represents the scientific development of this same idea, the signaling equipment being the culmination of many years of striving to overcome the limitations of visibility and audibility.

Coloring Of Structures

Color is applied to lighthouses and automatic light structures for the purpose of making them readily distinguishable from the background against which they are seen, and to distinguish one structure from others in the same general vicinity. Solid colors, bands of color, and various patterns are applied solely for these purposes.

Minor light structures are sometimes painted black or red, to indicate the sides of the channel which they mark, following the same system used in the coloring of buoys. When so painted, red structures mark the right side of the channel, and black structures the left side of the channel, entering from seaward.

Light Colors And Characteristics

The colors of the lights shown from lighthouses, and their characteristics or manner in which they flash, are for the purpose of distinguishing one light from others in the general vicinity and avoiding confusion with lights used for other purposes.

The length of the flashes and the intervals between may be accurately timed, and positive identification made by consulting the Light Lists. The colors of minor lights, when red or green, may also have the further significance of indicating the side of the channel which the light marks, red being on the right, and green on the left side entering from seaward.

Fog Signal Characteristics

Fog signals, both at lighthouses and on lightships, sound distinctive blasts. This is for the purpose of distinguishing one station from another. The characteristic of every fog signal is given in the Light Lists, and many of them are also given on the charts. All signals sound on a definite schedule, and positive identification may be made, even when the sending station is not visible, by timing the length of the blasts and the intervals between. With practice, mariners may also differentiate between the signals produced by the different types of apparatus.

Lightships

Lightships serve the same essential purpose as lighthouses. They take the form of ships only because they are to occupy stations at which it would be impracticable to build lighthouses. Hulls of all lightships in United States waters, excepting Ambrose Lightship, are now painted red with the name of the station in white on both sides. The superstructures are white, with the masts, lantern galleries, ventilators and stacks in buff.

All the signals, the masthead light, the fog signal, and the radiobeacon have distinctive characteristics, so that the lightship may readily be identified under all conditions. A riding-light on the forestay indicates the direction that the ship is heading, and as lightships ride to a single anchor, this also indicates the direction of the current.

Present day lightships are built of steel, with either steam or Diesel engine propulsion. Power for the operation of the signals is obtained from suitable auxiliary machinery. Each lightship has a crew of from 6 to 15 men.

Buoys

The primary function of buoys is to warn the mariner of some danger, some obstruction, or change in the contours of the sea bottom, that he may avoid the dangers and continue his course in safe waters.

The utmost advantage is obtained from buoys when they are considered as marking definitely identified spots, for if a mariner be properly equipped with charts, and knows his precise location at the moment, he can readily plot a safe course on which to proceed. Such features as size, shape, coloring, numbering, and signaling equipment, are but means to these ends of warning, guiding, and orienting.

These are all essential aids for any yachtsman.