of the vessel ahead, she shall give one short blast of the steam whistle, as a signal of such desire, and if the vessel ahead answers with one blast, she shall direct her course to starboard; or if she shall desire to pass on the left or port side of the vessel ahead, she shall give two short blasts of the steam whistle as a signal of such desire, and if the vessel ahead answers with two blasts, shall direct her course to port; or if the vessel ahead does not think it safe for the vessel astern to attempt to pass at that point, she shall immediately signify the same by giving several short and rapid blasts of the steam whistle, not less than four, and under no circumstances shall the vessel astern attempt to pass the vessel ahead until such time as they have reached a point where it can be safely done, when said vessel ahead shall signify her willingness by blowing the proper signals. The vessel ahead shall in no case attempt to cross the bow or crowd upon the course of the passing vessel.

Every vessel coming up with another vessel from any direction more than two points abaft her beam, that is, in such a position with reference to the vessel which she is overtaking that at night she would be unable to see either of that vessel's side lights, shall be deemed to be an overtaking vessel; and no subsequent alteration of the bearing between the two vessels shall make the overtaking vessel a crossing vessel within the meaning of the rules in this part, or relieve her of the duty of keeping clear of the overtaking vessel until she is finally past and clear.

As by day the overtaking vessel cannot always know with certainty whether she is forward of or abaft this direction from the other vessel she should, if in doubt, assume that she is an overtaking vessel and keep out of the way. (Former Pilot Rule VI.)

312.7 Vessels approaching each other at right angles or obliquely. When two steam vessels are approaching each other at right angles or obliquely so as to involve risk of collision, other than when one steam vessel is overtaking another, the steam vessel which has the other on her own port side shall hold her course and speed; and the steam vessel which has the other on her own starboard side shall keep out of the way of the other by directing her course to starboard so as to cross the stern of the other steam vessel, or, if necessary to do So, slacken her speed or stop or reverse.

If from any causes the conditions covered by this situation are such as to prevent immediate compliance with each other's signals, the misunderstanding or objection shall be at once made apparent by blowing the danger signal, and both steam vessels shall be stopped and backed if necessary, until signals for passing with safety are made and understood. (Former Pilot Rule VII.)

312.8 Meeting of steam and sailing vessels; right of way.When a steam vessel and a sailing vessel are proceeding in such directions as to involve risk of collision, the steam vessel shall keep out of the way of the sailing vessel. (Former Pilot Rule VIII.)

312.9 Avoidance of crossing ahead.-Every steam vessel which is directed by the rules in this part to keep out of the way of another vessel shall, if the circumstances of the case admit, avoid crossing ahead of the other. (Former Pilot Rule IX.)

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. (Former Pilot Rule X.)

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. (Former Pilot Rule XI.)

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. Rule XII.)

(Former Pilot

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. (Former Pilot Rule XIII.)

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 pre- . venting 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 2

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.

2 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 pp. 29 and 57.)

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.

Officers in Charge, Marine Inspection, 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, canal boats and scows 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, canal boats and scows 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. A tow of one such vessel shall be lighted as the last vessel of a tow.

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 except the last vessel in a tow 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, canal boats or scows towing alongside a steam vessel shall, if the deck, deck houses, or cargo of the barge, canal boat or scow 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, canal boat or scow; and if there is more than one barge, canal boat or scow abreast, the colored lights shall be displayed from the outer side of the outside barges, canal boats or scows.

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