The Rules of the Road – Maneuvering Sound Signals
Before we go into the Maneuvering and Sound signals it is first necessary to understand a few simple definitions as they pertain to this topic.
The word whistle means any sound-signaling appliance capable of producing the prescribed blasts. The term short blast means a blast of about one second’s duration.
The term prolonged blast means a blast from four to six second’s duration.
MANEUVERING AND WARNING SIGNALS
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 the Inland Rules, must indicate that maneuver by the following signals on the whistle:
When vessels in sight of one another are approaching each other and 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 must immediately indicate such doubt by giving at least five short, rapid blasts on the whistle.
A vessel nearing a bend or an area of a channel or fairway where other vessels may be obscured by an intervening obstruction must sound one prolonged blast. Such signal must be answered with a prolonged blast by any approaching vessel that may be within hearing around the bend or behind the intervening obstruction.
The one- and two-short-blast signals in the Inland Rules signify an intention of passage with one other vessel.
Upon hearing the one- or two-blast signal of the other, the vessel must, if in agreement, sound the same whistle signal and take the steps necessary to ensure a safe passing.
If, however, the vessel doubts the safety of the proposed maneuver, the vessel must sound the danger signal of at least five short, rapid blasts of the whistle. Each vessel will then take appropriate precautionary action until a safe passing agreement is made.
When in sight of another, a power-driven vessel intending to overtake another power-driven vessel must indicate its intention by the following signals on the whistle:
The power-driven vessel about to be overtaken will, if in agreement, sound a similar sound signal. If in doubt, the vessel must sound the danger signal of at least five short, rapid blasts.
A vessel that reaches agreement with another vessel in a meeting, crossing, or overtaking situation by using the radiotelephone, as prescribed by the Bridge-to-Bridge Radiotelephone Act (85 Stat. 165; 33 U.S.C. 1207), is not obligated to sound the whistle signals prescribed by this rule, but may do so. If agreement is not reached, then whistle signals must be exchanged in a timely manner and will prevail.
RESTRICTED VISIBILITY SOUND SIGNALS
In or near an area of restricted visibility, whether by day or night, the signals prescribed in this rule will be used as follows:
A vessel towed (or if more than one vessel is towed, the last vessel of the tow), if it is manned will, at intervals of not more than 2 minutes, sound four blasts in succession; namely, one prolonged blast followed by three short blasts. When practical, this signal must be made immediately after the signal made by the towing vessel.
When a pushing vessel and a vessel being pushed ahead are rigidly connected in a composite unit, they will be regarded as a power-driven vessel and give the signals prescribed earlier for a power-driven vessel making way through the water or a vessel underway but stopped and making no way through the water.
Remember that nothing in the Rules of the Road will exonerate any vessel, the owner, master, or crew, from the consequences of any neglect to carry lights or signals, station lookouts, or neglect to take any precaution that may be required by good seamanship.
You must take the ordinary precautions—carry the proper lights, use good judgment in your speed, and take any precautions necessary to avoid danger to your boat and its passengers. Be careful on the water and at all times and be safe.