When you failed to understand the signal and intention of another vessel what sound signal should we sound to warn the other vessel?

One prolonged blast is a warning signal (for example, used when coming around a blind bend or leaving the dock). Five (or more) short, rapid blasts are used to signal danger or to signal that you do not understand or you disagree with the other boater’s intentions.

Table of Contents Show

What does 3 short blasts of a boat horn mean?
How would a vessel communicate that does not understand your intentions?
When to use sound signals on a boat?
When do you need to use a sound signal?
What should you hear when a powerboat is underway in the fog?
Maneuvering Signals
Proper Sound Signals

What does 3 short blasts of a boat horn mean?

One short blast tells other boaters, “I intend to pass you on my left (port) side.” Two short blasts tell other boaters, “I intend to pass you on my right (starboard) side.” Three short blasts tell other boaters, “I am operating astern propulsion.” For some vessels, this tells other boaters, “I am backing up.”

How does a vessel communicate it doesn’t understand your intentions?

Five or more short and rapid blasts – Danger or doubt signal (I don’t understand your intent). Vessels indicate their intention to maneuver by using sound signals. If you do not agree with or understand clearly what the other vessel’s intentions are, you should sound the danger or doubt signal (5 short, rapid blasts).

How would a vessel communicate that does not understand your intentions?

Restricted Visibility One prolonged blast is a warning signal (for example, used when coming around a blind bend or exiting a slip). Five or more short rapid blasts signal danger, or signal that you do not understand or that you disagree with the other boater’s intentions.

When to use sound signals on a boat?

When two power-driven vessels encounter each other within one half mile, sound signals must be used. The initiating vessel indicates a maneuver, and the responding vessel agrees or disagrees. Entering or exiting a blind turn. Nearing an obstructed area. Leaving a dock or a berth.

What should you hear when a sailboat is underway?

A vessel underway under normal conditions does not need to make any sound signal.If the vessel ceases to make way it still does not make a sound signal unless special circumstances apply. a sailboat is underway in the fog. What sound signal should you hear? One prolonged blast plus two short blasts every two minutes.

When do you need to use a sound signal?

In international rules the signals are given when the maneuver is being executed. Vessels indicate their intention to maneuver by using sound signals. If you do not agree with or understand clearly what the other vessel’s intentions are, you should sound the danger or doubt signal (5 short, rapid blasts).

What should you hear when a powerboat is underway in the fog?

The sound signal that you should hear when a power boat is in the fog is one prolonged blast at intervals of no more than 2 minutes. What sound signal indicates that a power-driven vessel is underway in the fog?

Equipment for Sound Signals is based on the length of your boat as follows.

Boats less than 39.4 feet in length - must carry an efficient sound producing device. In general, this may be a bell, whistle, or air horn. Though guns--even pots and pans--can make a suitable sound signal useful in getting attention in an emergency, you should always carry the appropriate equipment.
Boats at least 39.4 feet to less than 65.6 feet in length - Must carry a whistle and a bell. The whistle must be audible for 1/2 nautical mile. The mouth of the bell must be at least 7.87 inches in diameter.

Sound signals are to be used only when vessels are in sight of each other and are meeting or crossing at a distance within half a mile of each other. These signals must never be used in fog or other conditions of reduced visibility, where the vessels are not visible to each other by eye. Only the fog signals listed under the Inland Rules, Rule 35 may be sounded at such time.

Sound signals are called "blasts". There are two different blasts used for warning and steering signals.

Short Blast - Lasts about one second.
Prolonged Blast - Lasts from four to six seconds.

Maneuvering Signals

There are different blasts combinations for various movements on the water that may use both short and prolonged blasts. 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 use the following sound signals.

One Short Blast - This means "I intend to leave you on MY port side". When you pass near another boat, you will manuever by leaving them on your left side as you pass. If you are behind another boat, going the same direction and about to overtake it, one short blast means: "I intend to pass you on YOUR starboard side, MY port side".
One Prolonged Blast - This means you are leaving a dock or departing your slip. It signals to others a change in status and that you are getting underway. A prolonged blast is also sounded when a vessel is approaching a bend in a river where vessels coming from another direction cannot be seen. It is sometimes referred to as the “blind bend signal".
Two Short Blasts - This means "I intend to leave you on MY starboard side". When you pass near another boat, you will manuever by leaving them on your right side as you pass. If you are behind another boat, going the same direction and about to overtake it, two short blasts means: "I intend to pass you on YOUR port side, MY starboard side."
Three Short Blasts - This means you are operating in astern propulsion, for example backing away from a dock
One Prolonged Blast + Three Short Blasts – This is technically two different signals in succession. One prolonged blast indicates you are getting under way, and three short blasts indicate you are backing up. This is what is sounded when you are departing a dock in reverse.
Five Short Blasts - This is the DANGER signal. Remember, that when you approach another vessel and hear either one or two short blasts, and you both understand their signal and can safely let them do it, then you are required to respond with the same signal in response. However, if you don't understand their intentions, or feel that their proposed maneuver is dangerous to either vessel, then you are required to sound the DANGER signal.

Note: Inland Rules regarding sound signals are occasionally different from International Rules. Inland Rules signal intended action and International Rules signal what you are actually doing. The following information reflects Inland Rules. If you travel overseas, you must learn the International Rules.

Proper Sound Signals

When you meet an oncoming vessel, and wish to pass port to port, you are required to sound one short blast with your horn. If the other boat is in agreement, they should respond with a similar blast.

If you approach another vessel head on, and wish to pass it on its starboard side, you are required to sound two short blasts with your horn. If the other vessel is in agreement, they should sound the same signal in response.

When you are planning on passing another vessel from behind, there are several things you must do. Any vessel that is overtaking another must keep out of the way of the vessel being overtaken. This means that you can't expect them to move, slow down, or change their course. If you plan on passing them on THEIR starboard side, you must sound one short blast. If they understand your signal and agree, they will sound one short blast in response. The vessel being overtaken has a responsibility to maintain course and speed in order to minimize the potential for collision.

When you are planning on passing another vessel from behind, there are several things you must do. Any vessel that is overtaking another must keep out of the way of the vessel being overtaken. This means that you can't expect them to move, slow down, or change their course. If you plan on passing them on THEIR PORT side, you must sound two short blasts. If they understand your signal and agree, they will sound two short blasts in response. The vessel being overtaken has a responsibility to maintain course and speed in order to minimize the potential for collision.

Note: These are not the only rules concerning sound signals in restricted visibility; there are additional rules concerning sound signals that may be found in the Rules of the Road or in Chapman's Piloting.