Rule 34 Manoeuvring and Warning Signals

Manoeuvring and Warning Signals — International

(a) When vessels are in sight of one another, a power-driven vessel underway, when manoeuvring as authorized or required by these Rules, shall indicate that manoeuvre by the following signals on her whistle:

— one short blast to mean “I am altering my course to starboard”,

— two short blasts to mean “I am altering my course to port”,

— three short blasts to mean “I am operating astern propulsion”.

(b) Any vessel may supplement the whistle signals prescribed in paragraph (a) of this Rule by light signals, repeated as appropriate, whilst the manoeuvre is being carried out:

(i) these light signals shall have the following significance:

— one flash to mean “I am altering my course to starboard”,

— two flashes to mean “I am altering my course to port”,

— three flashes to mean “I am operating astern propulsion”,

(ii) the duration of each flash shall be about one second, the interval between flashes shall be about one second, and the interval between successive signals shall be not less than 10 seconds,

(iii) the light used for this signal shall, if fitted, be an all-round white light, visible at a minimum range of five miles, and shall comply with the provisions of Annex I.

(c) When in sight of one another in a narrow channel or fairway:

(i) a vessel intending to overtake another shall in compliance with Rule 9(e)(i) indicate her intention by the following signals on her whistle:

— two prolonged blasts followed by one short blast to mean “I intend to overtake you on your starboard side”,

— two prolonged blasts followed by two short blasts to mean “I intend to overtake you on your port side”,

(ii) the vessel about to be overtaken when acting in accordance with Rule 9(e)(i) shall indicate her agreement by the following signal on her whistle;

— one prolonged blast, one short, one prolonged and one short blast, in that order.

(d) When vessels in sight of one another are approaching each other and from any cause either vessel fails to understand the intentions or actions of the other, or is in doubt whether sufficient action is being taken by the other to avoid collision, the vessel in doubt shall immediately indicate such doubt by giving at least five short and rapid blasts on the whistle. Such signal may be supplemented by a light signal of at least five short and rapid flashes.

(e) A vessel nearing a bend or an area of a channel or fairway where other vessels may be obscured by an intervening obstruction shall sound one prolonged blast. Such signal shall be answered with a prolonged blast by any approaching vessel that may be within hearing around the bend or behind the intervening obstruction.

(f) If whistles are fitted on a vessel at a distance apart of more than 100 metres, one whistle only shall be used for giving manoeuvring and warning signals.

Manoeuvring and Warning Signals — Canadian Modifications

(g) Notwithstanding paragraph (a), in the waters of the Great Lakes Basin, when power-driven vessels are in sight of one another and meeting or crossing at a distance within half a mile of each other, each vessel underway, when manoeuvring as authorized or required by these Rules

(i) shall indicate that manoeuvre by the following signals on her whistle:

— one short blast to mean “I intend to leave you on my port side”,

— two short blasts to mean “I intend to leave you on my starboard side”, and

— three short blasts to mean “I am operating astern propulsion”, and

(ii) shall, upon hearing the one or two blast signal, referred to in subparagraph (i), of the other vessel indicate her agreement by sounding the same whistle signal and taking the steps necessary to effect a safe passing. If, however, for any cause, a vessel on hearing a one or two blast signal referred to in subparagraph (i) doubts the safety of the proposed manoeuvre, she shall sound the signal specified in paragraph (d) and each vessel shall take appropriate precautionary action until a safe passing agreement is made.

(h) Notwithstanding paragraph (b), in the waters of the Great Lakes Basin, a vessel may supplement the whistle signals prescribed in paragraph (g) by light signals

(i) that have the following significance:

— one flash to mean “I intend to leave you on my port side”,

— two flashes to mean “I intend to leave you on my starboard side”,

— three flashes to mean “I am operating astern propulsion”, and

(ii) the duration of which shall be about one second for each flash.

(i) The light used for a signal referred to in paragraph (h), shall, if fitted, be one all-round white or yellow light, visible at a minimum range of two miles, synchronized with the whistle signal referred to in paragraph (g), and shall comply with section 12 of Annex I.

(j) Notwithstanding paragraph (c), in the waters of the Great Lakes Basin, when power-driven vessels are in sight of one another in a narrow channel or fairway,

(i) the vessel intending to overtake another shall, in compliance with Rule 9(i), indicate her intention by the following signals on her whistle:

— one short blast to mean “I intend to overtake you on your starboard side”,

— two short blasts to mean “I intend to overtake you on your port side”,

(ii) the vessel about to be overtaken when acting in accordance with Rule 9(i) shall, if in agreement, sound the same signal as given by the other vessel. If in doubt, she shall sound the signal prescribed in paragraph (d).

(k) In the Canadian waters of a roadstead, harbour, river, lake or inland waterway, a power-driven vessel of 12 metres or more in length that is leaving a dock or berth shall give a signal of one prolonged blast unless

(i) the vessel is a ferry making a scheduled departure from a dock or berth from which more than six daily scheduled departures are made,

(ii) the visibility is not less than 3 miles, and

(iii) the master of the ferry has used all available means appropriate to the prevailing circumstances and conditions to determine if the signal is needed for a safe departure and has determined that it is not.

(l) Notwithstanding this Rule and Rule 9, if positive mutual identification of the vessels has been made in the Canadian waters of a roadstead, harbour, river, lake or inland waterway, a vessel may use a bridge-to-bridge radiotelephone instead of the prescribed whistle signals to reach agreement in a meeting, crossing or overtaking situation. If agreement is not reached, then whistle signals shall be exchanged in a timely manner and shall prevail.