Just as lights beat a far-ranging role in expertise what other boats are doing, so do sounds. Understanding what friend hear is an additional step towards being a "complete mariner". Basically every boat is compelled to have actually some sound developing device. Over there is a an excellent deal of latitude in what kind of sound making machine you choose, however loud is good!

Legal Requirements

Equipment because that Sound signal is based upon the length of your boat as follows.

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Boats less than 39.4 feet in size - must carry an efficient sound developing device. In general, this may be a bell, whistle, or waiting horn. Despite guns--even pots and pans--can do a an ideal sound signal advantageous in acquiring attention in an emergency, you should constantly carry the proper equipment. Boats at least 39.4 feet to less than 65.6 feet in length - Must bring a whistle and a bell. The whistle need to be audible for 1/2 nautical mile. The mouth of the bell must be at least 7.87 customs in diameter. When and How come Sound off

Sound signals room to be offered only once vessels space in vision of every other and also are meeting or crossing at a street within half a mile of each other. This signals must never be provided in fog or other problems of diminished visibility, where the vessels room not clearly shows to each other by eye. Only the fog signals listed under the Inland Rules, rule 35 may be sound at such time.


Sound signals are referred to as "blasts". There are two different blasts provided for warning and steering signals.

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

Maneuvering Signals

There are various blasts combinations for miscellaneous movements top top the water that may use both brief and an extensive blasts. Once power-driven vessels room in vision of one another and meeting or cross at a street within fifty percent a mile of every other, each vessel underway, as soon as maneuvering together authorized or forced by the Inland rules have to use the following sound signals.

One brief Blast - This way "I intended to leave you ~ above MY harbor side". As soon as you happen near an additional boat, you will certainly manuever through leaving castle on her left side together you pass. If you room behind one more boat, walk the same direction and around to overtake it, one short blast means: "I intend to happen you on your starboard side, MY port side". One an extensive Blast - This method you are leaving a dock or departing your slip. It signals to others a change in status and that girlfriend are obtaining underway. A lengthy blast is additionally sounded as soon as a ship is approaching a bend in a river where vessels coming from an additional direction cannot be seen. That is periodically referred to as the “blind bend signal". Two brief Blasts - This means "I intended to leave you on my starboard side". Once you pass near another boat, you will manuever by leaving castle on your right side together you pass. If you are behind one more boat, walk the very same direction and about to overtake it, two brief blasts means: "I intended to pass you on your port side, my starboard side." Three quick Blasts - This way you room operating in astern propulsion, for instance backing far from a dock One an extensive Blast + Three brief Blasts – This is technically two various signals in succession. One prolonged blast suggests you are gaining under way, and three brief blasts indicate you are backing up. This is what is sounded as soon as you space departing a dock in reverse. Five quick Blasts - This is the peril signal. Remember, that as soon as you approach an additional vessel and hear either one or two short blasts, and you both recognize their signal and also can safely permit them carry out it, climate you are forced to respond through the exact same signal in response. However, if you don"t understand their intentions, or feel that their proposed maneuver is danger to one of two people vessel, then you are forced to sound the peril signal.

Note: Inland Rules concerning sound signals are occasionally various from international Rules. Inland rule signal intended activity and worldwide Rules signal what you space actually doing. The adhering to information reflects Inland Rules. If you travel overseas, friend must learn the international Rules.

Proper Sound Signals

Passing port to harbor

When you meet an oncoming vessel, and wish to happen port come port, you are required to sound one short blast v your horn. If the other watercraft is in agreement, they must respond v a similar blast.

pass Starboard come Starboard

If friend approach an additional vessel head on, and also wish to pass it on its starboard side, girlfriend are compelled to sound two quick blasts through your horn. If the other vessel is in agreement, they have to sound the very same signal in response.

overtaking on Portside

When you space planning top top passing another vessel from behind, over there are numerous things you need to do. Any vessel that is overtaking another must store out the the way of the vessel being overtaken. This way that friend can"t suppose them come move, slow-moving down, or adjust their course. If you arrangement on passing them on your starboard side, you should sound one short blast. If they know your signal and agree, they will sound one short blast in response. The vessel being overtaken has a responsibility to maintain course and also speed in stimulate to minimization the potential because that collision.

overtaking on Starboard

When you room planning top top passing one more vessel native behind, over there are number of things you should do. Any type of vessel that is overtaking one more must save out that the method of the vessel being overtaken. This means that friend can"t intend them to move, slow down, or change their course. If you plan on passing castle on THEIR harbor side, you should sound two quick blasts. If they recognize your signal and also agree, they will sound two quick blasts in response. The vessel gift overtaken has a responsibility to preserve course and also speed in bespeak to minimization the potential for collision.

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Note: These space not the just rules concerning sound signal in limited visibility; over there are extr rules concerning sound signals that may be uncovered in the rule of the roadway or in Chapman"s Piloting.