Rule 34 — Maneuvering and Warning Signals

33 CFR §83.34

Maneuvering and warning signals (Rule 34). (a) 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 maneuvering as authorized or required by these Rules: (i) Shall indicate that maneuver by the following signals on her whistle: (1) One short blast to mean “I intend to leave you on my port side”; (2) Two short blasts to mean “I intend to leave you on my starboard side”; and (3) Three short blasts to mean “I am operating astern propulsion”. (ii) Upon hearing the one or two blast signal of the other shall, if in agreement, sound the same whistle signal and take the steps necessary to effect a safe passing. If, however, from any cause, the vessel doubts the safety of the proposed maneuver,…

COLREGs Rule 34

Maneuvering and Warning Signals (a) When vessels are in sight of one another, a power-driven vessel underway, when maneuvering as authorized or required by these Rules, shall indicate that maneuver 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, while the maneuver 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 flas…

COLREGs Rule 34(a)

Maneuvering and Warning Signals (a) When vessels are in sight of one another, a power-driven vessel underway, when maneuvering as authorized or required by these Rules, shall indicate that maneuver 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”. Relationship to the Inland Rules: Inland Rule 34 differs from this rule — compare against 33 CFR 83.34 before answering a question that turns on which set applies.

COLREGs Rule 34(b)

Maneuvering and Warning Signals (b) Any vessel may supplement the whistle signals prescribed in paragraph (a) of this Rule by light signals, repeated as appropriate, while the maneuver 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 ten seconds; (iii) the light used for this signal shall, if fitted, be an all-round white light, visible at a minimum range of 5 miles, and shall comply with the provisio…

COLREGs Rule 34(c)

Maneuvering and Warning Signals (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, one short, one prolonged and one short blast, in that order. Sound and Light Signals Relationship to the Inland Rules: Inland Rule 34 differs from this rule — compare again…

COLREGs Rule 34(d)

Maneuvering and Warning Signals (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. Relationship to the Inland Rules: Inland Rule 34 differs from this rule — compare against 33 CFR 83.34 before answering a question that turns on which set applies.