"The words 'steam vessel' shall include any vessel propelled by machinery.

"A vessel is 'under way' within the meaning of these rules when she is not at anchor, or made fast to the shore, or aground.

"The word 'visible' in these rules, when applied to lights, shall mean visible on a dark night with a clear atmosphere.

"The words 'distinct blast' in these rules, when applied to whistle signals shall mean a clearly audible blast of any length.

"II-LIGHTS, AND SO FORTH

"RULE NUMBERED 2. The rules concerning lights shall be complied with in all weathers from sunset to sunrise, and during such time no other lights which may be mistaken for the prescribed lights, or impair their visibility, shall be exhibited.

"RULE NUMBERED 3. A steam vessel when towing another vessel or vessels alongside or by pushing ahead shall carry

"(a) On the starboard side a green light so constructed and fixed as to show the light from ahead and not more than half a point on the port bow to two points abaft the beam on the starboard side, and of such a character as to be visible at a distance of at least three miles.

"(b) On the port side a red light so constructed and fixed as to show the light from ahead and not more than half a point on the starboard bow, to two points abaft the beam on the port side, and of such a character as to be visible at a distance of at least three miles.

"(c) The said green and red side lights shall be fitted with inboard screens painted black and projecting at least three feet forward from the light, so as to prevent these lights from being seen more than half a point across the bow.

"(d) At or near the stern, where they can best be seen, two red lights in a vertical line, one over the other, not less than three feet apart, of such a character as to be visible from aft for a distance of at least two miles, and so screened as not to be visible forward of the beam.

"RULE NUMBERED 4. A steam vessel when towing another vessel or vessels on a hawser astern shall carry, in addition to the side lights described in rule 3 (a), (b), and (c) and at a greater height than those lights, in the forward half of the vessel, two bright white lights in a vertical line, one over the other, at least three feet apart. Each of these lights shall be so constructed as to show an unbroken light over an arc of twenty points of the compass, so fixed as to throw the light ten points on each side of the vessel, namely, from right ahead to two points abaft the beam on either side and of such a character as to be visible at a distance of at least three miles.

"RULE NUMBERED 5. A seagoing steam vessel underway shall carry lights as required by article 2, International Rules, as amended.

"RULE NUMBERED 6. A river steamer, by which is meant a river-type steam vessel with two smokestacks in an athwartship line, may carry, in lieu of the lights prescribed by rule 7 (a), the following lights, namely: One red light on the outboard side of the port smokestack and one green light on the outboard side of the starboard smokestack. Such lights shall show forward, aft, and abeam on their respective sides.

"RULE NUMBERED 7. (a) A steam vessel underway, except as otherwise provided in these rules, shall carry, in addition to side lights as described in rule 3 (a), (b), and (c), a central range of two white lights, the after light being carried at an elevation higher than the light at the head of the vessel. The headlight shall be so constructed as to show an unbroken light through twenty points of the compass, namely, from right ahead to two points abaft the beam on either side of the vessel, and the after light so as to show all around the horizon. "(b) The lights for barges, canal boats, scows, and other vessels of nondescript type, when in tow of steam vessels, and for ferryboats, shall be as prescribed by the Commandant, United States Coast Guard. "RULE NUMBERED 8. A sailing vessel under way, and any vessel being towed except barges, canal boats, scows, and other vessels of nondescript type when in tow of steam vessels, shall carry screened side lights as prescribed by rule 3, sections (a), (b), and (c), for a steam vessel, and a stern light as prescribed by rule 10.

"RULE NUMBERED 9. Whenever, as in the case of small vessels during bad weather, the green and red lights cannot be fixed, these lights shall be kept on deck, on their respective sides of the vessel, ready for instant exhibition, and shall, on the approach of or to other vessels, be exhibited on their respective sides in sufficient time to prevent collision, in such manner as to make them most visible, and so that the green light shall not be seen on the port side, nor the red light on the starboard side. To make the use of these portable lights more certain and easy, they shall each be painted outside with the color of the light they respectively contain, and shall be provided with suitable screens.

“RULE NUMBERED 10. A vessel which is being overtaken by another, except a steam vessel which already has one or more running lights visible from aft, shall show from her stern to such overtaking vessel a white light or a flare-up light.

"The white light required to be shown by this article may be fixed and carried in a lantern, but in such case the lantern shall be so constructed, fitted, and screened that it shall throw an unbroken light over an arc of the horizon of twelve points of the compass, namely, for six points from right aft on each side of the vessel, so as to be visible at a distance of at least two miles.

"RULE NUMBERED 11. (a) Sailing pilot vessels, when engaged on their station on pilotage duty, and not at anchor, shall not show the lights required for other vessels, but shall carry a white light at the masthead, visible all around the horizon, at a distance of at least three miles, and shall also exhibit a flare-up light or flare-up lights at short intervals, which shall never exceed ten minutes.

"On the near approach of or to other vessels they shall have their side lights lighted, ready for use, and shall flash or show them at short intervals to indicate the direction in which they are heading, but the green light shall not be shown on the port side, nor the red light on the starboard side.

"A sailing pilot vessel of such a class as to be obliged to go alongside of a vessel to put a pilot on board may show the white light instead of carrying it at the masthead, and may, instead of the side lights above mentioned, have at hand, ready for use, a lantern with a green glass on the one side and a red glass on the other, to be used as prescribed above.

"(b) A steam pilot vessel when engaged on her station on pilotage duty and not at anchor shall, in addition to the lights and flares required for sailing pilot vessels, carry, at a distance of eight feet below her white masthead lights, a red light, visible all around the horizon at a distance of at least three miles, and also the side lights required to be carried by vessels when under way.

"(c) All pilot vessels, when engaged on their stations on pilotage duty and at anchor, shall carry the lights and show the flares prescribed above, except that the side lights shall not be shown.,

"When not engaged on their stations on pilotage duty they shall carry the same lights as other vessels of their class and tonnage.

"RULE NUMBERED 12. Motorboats, when not engaged in towing, shall be lighted as provided by the Motorboat Act of April 25, 1940, as amended. When towing, they shall be subject to the same provisions for lighting as other steam vessels towing.

"RULE NUMBERED 13. (a) A vessel under one hundred and fifty feet in length, when at anchor, and not moored to the bank or wharf, shall carry forward, where it can best be seen, a white light in a lantern so constructed as to show a clear, uniform, and unbroken light visible all around the horizon at a distance of at least two miles: Provided, That the Secretary of the Army may, after investigation, by rule, regulation, or order, designate such areas as he may deem proper as 'special anchorage areas'; such special anchorage areas may from time to time be changed, or abolished, if after investigation the Secretary of the Army shall deem such change or abolition in the interest of navigation: Provided further, That vessels not more than sixty-five feet in length when at anchor in any such special anchorage area shall not be required to carry or exhibit the white light required by this article.

(b) A vessel of one hundred and fifty feet or upward in length, when at anchor, and not moored to the bank or a wharf, shall carry in the forward part of the vessel, where it can best be seen, one such light, and at or near the stern of the vessel, and at such a height that it shall not be less than fifteen feet lower than the forward light, another such light.

"RULE NUMBERED 14. The exhibition of any light on board of a vessel of war of the United States or a Coast Guard cutter may be suspended whenever, in the opinion of the Secretary of the Navy, the commander in chief of a squadron, or the commander of a vessel acting singly, the special character of the service may require it.

"RULE NUMBERED 15. All signals prescribed by this article for vessels under way shall be given

"By 'steam vessels' on the whistle or siren.

"By sailing vessels and 'vessels towed' on the foghorn.

"A steam vessel shall be provided with an efficient whistle or siren, sounded by steam or by some substitute for steam, so placed that the sound may not be intercepted by any obstruction; also with an efficient bell. A sailing vessel of twenty gross tons or upward shall be provided with a similar bell.

"In fog, mist, falling snow, heavy rainstorms, or any other condition similarly restricting visibility, whether by day or night, the signals described by this article shall be used as follows, namely:

"(a) A steam vessel under way and towing another vessel or vessels shall sound, at intervals of not more than one minute, three distinct blasts of the whistle, of approximately equal length.

"(b) A steam vessel under way without a tow shall sound, at intervals of not more than one minute, three blasts of the whistle, the first two blasts to be approximately of equal length, the last blast to be longer.

"(c) A steam vessel, with or without a tow, lying to, by which is meant holding her position near or against the bank by using her engines, or temporarily moored to the bank, when a fog signal or other sound is heard indicating the approach of another vessel, shall, if lying to on the right bank, give one tap of the bell to indicate her presence, and if lying to on the left bank, two taps of the bell, at intervals of not more than one minute, such signals to continue until the approaching steam vessel has passed. Right and left bank is understood as facing downstream or with the flow of the current.

"(d) A vessel when at anchor shall, at intervals of not more than one minute, ring the bell rapidly for about five seconds.

"RULE NUMBERED 16. Every steam vessel shall, in fog, mist, falling snow, heavy rainstorms, or any other condition similarly restricting visibility, whether by day or night, go at a moderate speed. A steam vessel hearing, apparently forward of her beam, the fog signal of another vessel shall at once reduce her speed to bare steerageway, and navigate with caution until the vessels shall have passed each other.

"RULE NUMBERED 17. When two sailing vessels are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other, as follows, namely:

"(a) A vessel which is running free shall keep out of the way of a vessel which is close-hauled.

"(b) A vessel which is close-hauled on the port tack shall keep out of the way of a vessel which is close-hauled on the starboard tack.

"(c) When both are running free, with the wind on different sides, the vessel which has the wind on the port side shall keep out of the way of the other.

(d) When both are running free, with the wind on the same side, the vessel which is to the windward shall keep out of the way of the vessel which is to the leeward.

"(e) A vessel which has the wind aft shall keep out of the way of the other vessel.

"III-STEERING AND SAILING RULES

"PRELIMINARY-RISK OF COLLISION

"Risk of collision can, when circumstances permit, be ascertained by carefully watching the bearing of an approaching vessel. If the bearing does not appreciably change such risk should be deemed to exist.

"RULE NUMBERED 18. (a) When two steam vessels are meeting end on, or nearly end on, so as to involve risk of collision, except when one steam vessel is ascending and the other descending a river, it shall be the duty of each to pass on the port side of the other, and to alter course to starboard sufficiently so that this can be done in safety. This maneuver shall require an exchange of one-blast signals when the vessels are not less than one-half mile apart, and either vessel shall blow the first signal which the other shall promptly answer.

"(b) When an ascending steam vessel is approaching a descending steam vessel on a river, the signals for passing shall be one distinct blast of the whistle by each vessel if passing port to port, and two distinct blasts of the whistle if passing starboard to starboard.

"The pilot of the ascending steam vessel shall give the first signal for passing, which shall promptly be answered by the same signal by the pilot of the descending steam vessel, if safe to do so, and both shall be governed accordingly; but if the pilot of the descending steam vessel deems it dangerous to take the side indicated by the ascending steam vessel, he shall immediately signify that fact by sounding four or more short and rapid blasts, the danger signal, and it shall be the duty of the pilot of the ascending steam vessel to answer by a similar danger signal and the engines of both shall immediately be stopped and backed, if necessary, until signals for passing are given, answered, and understood. After sounding the danger signal by both vessels, the pilot of the descending steam vessel shall indicate by his whistle the side on which he desires to pass, and the pilot of the ascending steam vessel shall govern himself accordingly, the descending steam vessel being entitled to the right-of-way.

"The pilot of the descending steam vessel shall not blow the first signal, except that if the other vessel has not whistled when the steam vessels, or the forward end of their tows, if being pushed ahead, are within one-half mile of each other, he shall blow the first danger signal, which shall be promptly answered by a danger signal by the ascending vessel; but whether answered or not, the pilot of the descending vessel shall indicate the side on which he desires to pass, and both vessels shall be governed accordingly.

"RULE NUMBERED 19. (a) When two steam vessels are crossing so as to involve risk of collision, other than when one vessel is overtaking another, the vessel which has the other to starboard shall keep out of the way of the other. Either vessel shall give, as a signal of intention to comply with this rule, one distinct blast of her whistle, which the other vessel shall answer with a similar blast: Provided, however, That a steam vessel descending a river and towing another vessel or vessels shall be deemed to have the right-of-way over any steam vessel crossing the river, and shall give as a signal of her intention to hold on across the bow of the other vessel, three distinct blasts of the whistle. The crossing vessel shall immediately reply with a similar signal, and shall keep clear by stopping or going under the stern of the descending vessel.

"(b) If from any cause the conditions covered by these situations are such as to prevent immediate compliance with each other's signals, the misunderstanding or objection shall be at once made apparent by blowing four or more short and rapid blasts, the danger signal, and both steam vessels shall be stopped and backed if necessary until signals for passing with safety in accordance with these rules are given, answered, and understood.

"RULE NUMBERED 20. When a steam vessel and a sailing vessel are proceeding in such directions as to involve risk of collision, except when the sailing vessel is overtaking the steam vessel, the steam vessel shall keep out of the way of the sailing vessel.

"RULE NUMBERED 21. Every steam vessel, when approaching another vessel so as to involve risk of collision, shall slacken her speed, or, if necessary, stop and reverse.