51. Rules Briefly Stated. The foregoing rules pertaining to the manuevering of vessels meeting or overtaking one another whether by day or night may be summed up in the following brief and concise presentation:

When meeting end on or nearly so, alter course to starboard and pass on port side of other vessel. Follow this rule at night whenever both side lights of another vessel are visible forwards of the beam.

When crossing, the vessel having the other on her starboard side shall keep out of the way of the other.

A power vessel shall keep out of the way of a sailing vessel.

In narrow channels do not overtake and pass another vessel.

In all weathers, except as specified, the following whistle signals shall indicate the courses required herein. When receiving a signal, answer with the same signal.

One blast means: I am directing my course to starboard.
Two blasts mean: I am directing my course to port.

Three blasts mean: My engines are full speed astern.

Never sound a reverse or cross signal. If inadvisable to accept any signal, or if the same is not understood, sound not less than four short and rapid blasts of the whistle. In this case both vessels shall, if required, reduce speed or stop, or reverse, until proper signals are given and understood.

When approaching a bend in a channel sound one long blast.

Give whistle signals only when in sight of signaled vessels by day or night.

In thick weather or fog conditions give fog signals only.

Distress signals, to be given when assistance is required from other vessels or from shore are:

1. In the daytime, a continuous sounding with any fog-signal apparatus, firing a gun, or distance signal consisting of square flag and either above or below it a ball, or anything resembling a ball.

2. At night, flames on the vessel, continuous sounding of any fog-signal apparatus, firing a gun, rockets or shells fired, one at a time, at short intervals.

UNITED STATES BUOYAGE SYSTEM

52. When approaching a channel or fairway from seawards, red buoys with even numbers will be found on the starboard side of the channel, and must be kept to starboard when passing in. Black buoys with odd numbers will be found on the port side of the channel, and must be kept to port when passing in. Buoys painted with red and black horizontal stripes indicate

obstructions, with channel ways on either side of them, and may be passed on either side when entering.

Buoys painted with white and black perpendicular stripes are placed in the deepest part of the channel and should therefore be passed close by.

53.

Other distinguishing marks on buoys may be used to mark particular spots; a description of these is given in the printed list of buoys issued by the United States Light

house Board.

Nun Buoys

FIG. 12

Perches, with balls, cages, etc., when placed on buoys, signify turning points in the channel, the color and number indicating on which side they shall be passed.

Different channels in the same bay, sound, river, or harbor are marked, as far as practicable, by different types of buoys. Principal channels are marked by nun buoys; secondary channels by can buoys; and minor channels by spar buoys. When there is but one channel, nun buoys, properly colored and numbered, are usually placed on the starboard side, and can buoys on the port side. Day beacons, stakes, and spindles (except such as are on the sides of channels, which will be colored like buoys) are constructed and distinguished with special reference to each locality, and particularly in regard to the background upon which they are projected.

Wherever practicable, the towers, beacons, buoys, spindles, and all other aids to navigation, are arranged in the buoy list of the Lighthouse Board in the order in which they are passed by vessels entering from seawards. The buoys in thor

oughfares and passages between the islands along the coast of Maine are numbered and colored for entering from eastwards. Vessels approaching or passing lightships in thick foggy weather will be warned of their proximity by the alternate ringing of a bell and the sounding of a foghorn on board the lightship at intervals not exceeding 5 minutes.

54. Types of Buoys.-Floating buoys vary in character and construction according to their purpose or the distance at which they should be seen. The simpler forms are the wooden and iron spar buoys and iron can and nun buoys. For warning in foggy weather, buoys are sometimes fitted with bells, whistles and submarine bells, all actuated by the motion of the sea.

Some important buoys are lighted, usually by means of oil gas compressed in the buoy itself or by acetylene gas compressed in tanks placed in the buoy or generated in it. The light is often flashing or oscillating, for the purpose both of

providing a distinction mark and of prolonging the supply of gas. The use of gas buoys has greatly increased in recent years there being at present more than 346 in the United States. They are very valuable as aids to navigation and often obviate the necessity of establishing expensive light vessels or range lights on shore. Sometimes such a buoy can be placed at small cost where the construction and building of a solid structure would require a vast sum of money. Some of the different types of buoys are shown in Figs. 12, 13, 14, and 15.

55. Buoys are painted and numbered to indicate their position and the side on which they should be passed as already described. Sometimes, buoys may be damaged or sunk or dragged or broken from their moorings by vessels, tows, wreckage, or ice. To keep buoys in order and in their proper position is the principal functions of the lighthouse tenders maintained by the government.

Motor-boat operators should bear in mind that to use a buoy beacon or floating aid to navigation for mooring purposes with boat or raft of any kind is punishable in most states by heavy fines or by fines and imprisonment; except when used in lifesaving. To remove, damage, or destroy any beacon or buoy is punishable by greater penalties.

WEATHER INDICATIONS

56. Wind and weather conditions are by no means the least important matters to motor-boat navigators. A day's trip is often marred by bad weather that might have been foreseen or anticipated with reasonable certainty had attention been given to indications that seldom go wrong. It is true that professional weather forcasters do sometimes make mistakes in foretelling weather but, as a rule, they do not go far astray and on an average 85 per cent. of their predictions are successful.

By availing himself of imformation sent out by the Weather Bureau and making a close and critical observation of local atmospheric conditions, the motor-boat operator may know what weather may be expected within the next 24 hours. To do this he must first study the weather forecasts, which are published in almost every daily local newspaper, and, second, learn how to use the barometer and observe prevailing aspects of weather and sky.

57. Weather Bureau Forecasts.-The Weather Bureau forecasts are based on simultaneous observations of local weather conditions taken daily at 8 A. M. and 8 P. M., 75th meridian time, at about two hundred regular observing stations