On the other hand buoys may be huge structures of steel many tons in weight, forty feet from top to bottom, ten feet in diameter, and complex in their equipment of lights or whistles or bells. Or they may be great barrel-like steel floats, or conical ones, or great turnip-shaped floats. Some are spherical, some are of stranger shapes. They may be red or black or green. Some are striped, with weird decorations gracing their tops. Some support small triangles or spheres, some crosses, some paint-brush-like affairs. But each one has its particular uses, and one should hesitate to pass a buoy unless the thing it stands for is understood.
In United States waters, for instance, one needs to know that in coming in from sea a ship should pass with the red buoys, which are conical in shape and are called “nun” buoys, on the starboard, or right side. These buoys are further distinguished by being numbered with even numbers. At the same time all “can” buoys, which are black and cylindrical, with odd numbers painted on them, should be kept to the port or left side. Sometimes “spar” buoys replace these, but the buoys to starboard will always be red, the buoys to port black, as the ship comes in from sea.
Buoys painted with red and black horizontal lines mark obstructions with channels on both sides. Buoys with white and black perpendicular stripes sometimes mark the middle of a channel and a ship should pass close to them. Buoys marking quarantine are yellow, while buoys marking the limits of anchorages are usually white.
AUTOMATIC BUOYS
The whistle buoy at the left utilizes the motion of the waves to blow a whistle. The light buoy in the centre has an automatic light that burns gas stored in the body of the buoy. The bell buoy at the right carries a bell, against which four clappers are pounded by the action of the waves.
The whistling buoys and lighted buoys are, perhaps, the most interesting of the lot. Imagine a huge steel top, with a whistle placed at its point, and a large steel tube running through it from top to bottom, extending more than the height of the top above it. Imagine this top ten or twelve feet in diameter, and, with the tube, forty feet in height. Imagine this, then, floating in the water, point up, and with the tube below the surface. The end of the tube below the water is open. The end on which the whistle is mounted contains two openings. In one of these the whistle is placed. The other opening is closed by a valve which permits air to enter, but closes when the air tries to escape. This buoy is anchored in the water, and as the waves toss it up and down they rise and fall in the lower part of the tube. As they rise the air inside is compressed and is blown through the whistle causing it to sound. As the water in the tube falls, air is drawn through the valve, and again the waves force it through the whistle. This ponderous but simple “whistling” buoy requires no supplies and almost no attention. Periodically it is visited by a tender and is temporarily relieved of work while it is taken to the repair shop to be examined, repaired, and painted. Aside from that it needs no attention, yet constantly it moans as the waves sweep under it, and the greater the waves the greater is the volume of its sound.
Bell buoys are equally simple and effective. These buoys are surmounted by a framework of steel from which a large bell is rigidly suspended. Several “clappers” are hinged about it so that, no matter how a wave may move the buoy, a clapper strikes the bell.
The light buoys are more complicated and more diverse. There are more than a dozen different sizes and shapes, and the fuel is usually compressed oil gas or compressed acetylene gas. The buoys themselves—that is, the floats—may be of almost any shape. Some are spherical, some cylindrical. Some are long and thin, and others short and fat, but each one has a framework or a shaft of steel extending from ten to twenty feet above it. At the top of this the light is fixed, while the body of the buoy holds the gas. These lights flash intermittently, the gas, which is under pressure, operating a valve while a tiny “pilot light” in the burner remains always burning in order to ignite the gas when it is turned on to cause each flash. Some of these buoys carry a supply of fuel great enough to last for three months, and during that time they flash their lights every few seconds without fail, marking a danger or a channel, and are visible, sometimes, from distances of several miles.
Thus the dangers of the sea are marked by lighthouses, lightships, and buoys, while harbour entrances and channels are marked as well. This has been done in order to save life and property and in order to expedite the passages of ships. No more do captains have to depend on guess and luck. Their accurate sextants and chronometers tell them where they are on the trackless sea. Their barometers tell them of approaching storms. Their compasses tell them their directions.