In fog, mist, falling snow, or heavy rain storms, whether by day or night, the signals described in this article shall be used as follows, namely:
(_a_) A steam vessel under way shall sound, at intervals of not more than one minute, a prolonged blast.
(_c_) A sailing vessel under way shall sound, at intervals of not more than one minute, when on the starboard tack, one blast; when on the port tack, two blasts in succession, and when with the wind abaft the beam, three blasts in succession.
(_d_) A vessel when at anchor shall, at intervals of not more than one minute, ring the bell rapidly for about five seconds.
(_e_) A steam vessel when towing, shall, instead of the signals prescribed in subdivision (_a_) of this article, at intervals of not more than one minute, sound three blasts in succession, namely, one prolonged blast followed by two short blasts. A vessel towed may give this signal and she shall not give any other.
(_f_) All rafts or other water craft, not herein provided for, navigating by hand power, horse power, or by the current of the river, shall sound a blast of the fog horn, or equivalent signal, at intervals of not more than one minute.
ART. 16. Every vessel shall, in a fog, mist, falling snow, or heavy rain storms, 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.
INLAND RULES: IV. STEERING AND SAILING RULES
Risk of collision can, when circumstances permit, be ascertained by carefully watching the compass bearing of an approaching vessel. If the bearing does not appreciably change, such risk should be deemed to exist.
ART. 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 closehauled.
(_b_) A vessel which is closehauled on the port tack shall keep out of the way of a vessel which is closehauled on the starboard tack.