312.10 Keeping to right in narrow channels.-In narrow channels every steam vessel shall, when it is safe and practicable, keep to that side of the fairway or mid-channel which lies on the starboard side of such vessel.

312.11 Departure from rules.--In obeying and construing the rules in this part due regard shall be had to all dangers of navigation and collision, and to any special circumstances which may render a departure from said rules necessary in order to avoid immediate danger.

312.12 Fog signals.-In fog, mist, falling snow, or heavy rainstorms, whether by day or night, signals shall be given as follows:

A steam vessel under way, except when towing other vessels or being towed, shall sound, at intervals of not more than 1 minute, on the whistle or siren, a prolonged blast.

A steam vessel when towing other vessels shall sound, at intervals of not more than 1 minute, on the whistle or siren, three blasts in succession, namely, one prolonged blast followed by two short blasts.

A vessel towed may give, at intervals of not more than 1 minute, on the fog horn, a signal of three blasts in succession, namely, one prolonged blast followed by two short blasts, and she shall not give any other.

A vessel when at anchor shall, at intervals of not more than 1 minute, ring the bell rapidly for about 5 seconds.

312.13 Speed in fog; posting of rules; diagrams-(a) Moderate speed in fog.—Every steam vessel shall, in a fog, mist, falling snow, or heavy rainstorms, go at a moderate speed, having careful regard to the existing circumstances and conditions.

A steam vessel hearing, apparently forward of her beam, the fog signal of a vessel the position of which is not ascertained shall, so far as the circumstances of the case admit, stop her engines and then navigate with caution until danger of collision is over.

(b) Posting of pilot rules. On steam and other motor vessels of over 100 gross tons, two copies of the placard form of the rules (Form 803) in this part shall be kept posted up in conspicuous places in the vessel, one copy of which shall be kept posted up in the pilothouse. On steam and other motor vessels of over 25 gross tons and not over 100 gross tons, two copies of the placard form of the pilot rules shall be kept on board, one copy of which shall be kept posted up in the pilothouse. On steam and other motor vessels of 25 gross tons and under, and of more than 10 gross tons, two copies of the placard form of the pilot rules shall be kept on board, and, where practicable, one copy thereof shall be kept conspicuously posted up in the vessel. On steam and other motor vessels of not more than 10 gross tons, two copies of the pamphlet form of the pilot rules shall be kept on board, and, where practicable, one copy thereof shall be kept conspicuously posted up in the vessel.

Nothing herein contained shall require copies of the pilot rules to be carried on board any motorboat as defined by section 1 of the act of April 25, 1940. (54 Stat. 163-167; 46 U. S. Č. 526-526t.)

(c) Diagrams. The following diagrams are intended to illustrate the working of the system of colored lights and pilot rules.

FIRST SITUATION

Here the two colored lights visible to each will indicate their direct approach "head and head" toward each other. In this situation it is a standing rule that both shall direct their courses to starboard and pass on the port side of each other, each having previously given one blast of the whistle.

SECOND SITUATION

In this situation the red light only will be visible to each, the screens preventing the green lights from being seen. Both vessels are evidently passing to port of each other, which is rulable in this situation, each pilot having previously signified his intention by one blast of the whistle.

THIRD SITUATION

In this situation the green light only will be visible to each, the screens preventing the red light from being seen. They are therefore passing to starboard of each other, which is rulable in this situation, each pilot having previously signified his intention by two blasts of the whistle.

FOURTH SITUATION

In this situation one steam vessel is overtaking another steam vessel from some point within the angle of two points abaft the beam of the overtaken steam vessel. The overtaking steam vessel may pass on the starboard or port side of the steam vessel ahead after the necessary signals for passing have been given with assent of the overtaken steam vessel, as prescribed in § 312.6.

1

FIFTH SITUATION

In this situation two steam vessels are approaching each other at right angles or obliquely in such manner as to involve risk of collision, other than where one steam vessel is overtaking another. The steam vessel which has the other on her own port side shall hold course and speed, and the other shall keep clear by crossing astern of the steam vessel that is holding course and speed, or, if necessary to do so, shall slacken her speed, stop, or reverse.

RULES FOR LIGHTS FOR CERTAIN CLASSES OF VESSELS NAVIGATING HARBORS, RIVERS, AND INLAND WATERS EXCEPT GREAT LAKES AND THEIR CONNECTING AND TRIBUTARY WATERS AS FAR EAST AS MONTREAL AND THE RED RIVER OF THE NORTH AND RIVERS EMPTYING INTO THE GULF OF MEXICO AND THEIR TRIBUTARIES 3

312.14 Lights; time for.-The following rules in this part concerning lights shall be complied with in all weathers from sunset to sunrise.

312.15 Ferryboats. Ferryboats propelled by machinery and navigating the harbors, rivers, and other inland waters of the United States, except the Great Lakes and their connecting and tributary waters as far east as Montreal and the Red River of the North and rivers emptying into the Gulf of Mexico and their tributaries, shall carry the range lights and the colored side lights required by law to be carried on steam vessels navigating those waters, except that double-end ferryboats shall carry a central range of clear, bright, white lights, showing all around the horizon, placed at equal altitudes forward and aft, also on the starboard side a green light, and on the port side a red light, of such a character as to be visible on a dark night with a clear atmosphere at a distance of at least 2 miles, and so constructed as to show a uniform and unbroken light over an arc of the horizon of 10 points of the compass, and so fixed as to throw the light from right ahead to 2 points abaft the beam on their respective sides.

See act of Congress approved April 25, 1940 (54 Stat. 164; 46 U. S. C. 526b), prescribing lights that shall be carried by certain classes of vessels of not more than 65 feet in length, amendatory of these rules. (See p. 29.)

The green and red lights shall be fitted with inboard screens projecting at least 3 feet forward from the lights, so as to prevent them from being seen across the bow.

Merchant Marine Inspectors in Charge in districts having ferryboats shall, whenever the safety of navigation may require, designate for each line of such boats a certain light, white or colored, which will show all around the horizon, to designate and distinguish such lines from each other, which light shall be carried on a flagstaff amidships, 15 feet above the white range lights.

312.16 Lights for barges and canal boats in tow of steam vessels on certain inland waters on the seaboard, except the Hudson River and adjacent waters and Lake Champlain. On the harbors, rivers, and other inland waters of the United States, except the Great Lakes and their connecting and tributary waters as far east as Montreal and the Red River of the North and rivers emptying into the Gulf of Mexico and their tributaries, and except on the waters of the Hudson River and its tributaries from Troy to the boundary lines of New York Harbor off Sandy Hook as defined pursuant to section 2 of the act of Congress of February 19, 1895 (28 Stat. 672; 33 U. S. C. 151), the East River, and Long Island Sound (and the waters entering thereon, and to the Atlantic Ocean), to and including Narragansett Bay, R. I., and tributaries, and Lake Champlain, barges (except scows) and canal boats in tow of steam vessels shall carry lights as follows:

Barges and canal boats towing astern of steam vessels, when towing singly, or what is known as tandem towing, shall each carry a green light on the starboard side and a red light on the port side, and a white light on the stern, except that the last vessel of such tow shall carry two lights on her stern, athwartship, horizontal to each other, not less than 5 feet apart, and not less than 4 feet above the deck house, and so placed as to show all around the horizon.

When two or more boats are abreast, the colored lights shall be carried at the outer sides of the bows of the outside boats. Each of the outside boats in last tier of a hawser tow shall carry a white light on her stern.

The white light required to be carried on stern of a barge or canal boat carrying red and green side lights shall be carried in a lantern so constructed that it shall show an unbroken light over an arc of the horizon of 12 points of the compass, namely, for 6 points from right aft on each side of the vessel, and shall be of such a character as to be visible on a dark night with a clear atmosphere at a distance of at least 2 miles.

Barges or canal boats towing alongside a steam vessel shall, if the deck, deck houses, or cargo of the barge or canal boat be so high above water as to obscure the side lights of the towing steamer when being towed on the starboard side of the steamer, carry a green light upon the starboard side; and when towed on the port side of the steamer, a red light on the port side of the barge or canal boat; and if there is more than one barge or canal boat abreast, the colored lights shall be displayed from the outer side of the outside barges or canal boats.

Barges or canal boats shall, when being propelled by pushing ahead of a steam vessel, display a red light on the port bow and a green

light on the starboard bow of the head barge or canal boat, carried at a height sufficiently above the superstructure of the barge or canal boat as to permit said side lights to be visible; and if there is more than one barge or canal boat abreast, the colored lights shall be displayed from the outer side of the outside barges or canal boats.

The colored side lights referred to in the rules in this part for barges and canal boats in tow shall be fitted with inboard screens, so as to prevent them from being seen across the bow, and of such a character as to be visible on a dark night, with a clear atmosphere, at a distance of at least 2 miles, and so constructed as to show a uniform and unbroken light over an arc of the horizon of 10 points of the compass, and so fixed as to throw the light from right ahead to 2 points abaft the beam on either side. The minimum size of glass globes shall not be less than 6 inches in diameter and 5 inches high in the clear.

Scows when being towed by steam vessels on the waters covered by the first paragraph of this section shall carry a white light at each end of each scow, except that when such scows are massed in tiers, two or more abreast, each of the outside scows shall carry a white light on its outer bow, and the outside scows in the last tier shall each carry, in addition, a white light on the outer part of the stern. The white light shall be carried not less than 8 feet above the surface of the water, and shall be so placed as to show an unbroken light all around the horizon, and shall be of such a character as to be visible on a dark night with a clear atmosphere at a distance of at least 5 miles.

312.17 Lights for barges and canal boats in tow of steam vessels on the Hudson River and adjacent waters and Lake Champlain.-All nondescript vessels known as scows, car floats, lighters, and vessels of similar type, navigating the waters referred to in the following rules, shall carry the lights required to be carried by barges and canal boats in tow of steam vessels, as prescribed in such rules. Barges and canal boats, when being towed by steam vessels on the waters of the Hudson River and its tributaries from Troy to the boundary lines of New York Harbor off Sandy Hook, as defined pursuant to section 2 of the act of Congress of February 19, 1895 (28 Sta. 672; 33 U. S. C. 151), the East River and Long Island Sound (and the waters entering thereon, and to the Atlantic Ocean), to and including Narragansett Bay, R. Í., and tributaries, and Lake Champlain, shall carry lights as follows:

(a) Barges and canal boats being towed astern of steam vessels when towing singly shall carry a white light on the bow and a white light on the stern.

SINGLY

(b) When towing in tandem, "close up," each boat shall carry a white light on its stern and the first or hawser boat shall, in addition, carry a white light on its bow.