three toots to exit berth

[koliver]

When in doubt, read the actual rule:
International Regulations for Preventing Collisions a Sea, 1972 "COLREGS"

Rule 34
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”.

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.

As has been noted above, almost no one actually observes this rule, but if ever in a situation of poor visibility, it is a better practice to use the horn as "required" and so avoid the possibility of an "At Fault" collision.

 

[psneeld]

Taken behind Key Largo a couple minutes ago.

Paint is wearing off from so much use.....

 

[aboatman]

.......... In the Canadian waters of a roadstead, harbour, river, lake or inland waterway, a power-driven vessel of 12 metres or more in length..................

At least in this case, it's specified that the rule applies to boats of a certain minimum size. In the USA, it technically would apply to a runabout or motorized jon boat.

 

[BandB]

I just picture a 1500 boat marina and everyone doing three toots on a holiday. That is not the law or the intent. It's seldom needed. If you're backing out of a slip and someone is coming, you don't sound your horn, you let them pass first. If you're backing out and can't see, fix that. You sound warnings on winding rivers.

95% of all horn blowing when backing out or leaving the dock that I've heard has been ferries. When they do so, I interpret it as "I'm coming through, whether you're ready or not, so get out of my way now."

 

[AusCan]

I just picture a 1500 boat marina and everyone doing three toots on a holiday. That is not the law or the intent. It's seldom needed. If you're backing out of a slip and someone is coming, you don't sound your horn, you let them pass first. If you're backing out and can't see, fix that. You sound warnings on winding rivers.

95% of all horn blowing when backing out or leaving the dock that I've heard has been ferries. When they do so, I interpret it as "I'm coming through, whether you're ready or not, so get out of my way now."

I agree.

Although over here, the ferries don't use their horn unless there is a visibility issue or there is someone blocking there path.

If I heard a horn from a recreational trawler coming out of a berth, I interpret it as "Hey everyone, look at me, look at me"

 

[markpierce]

...

If I heard a horn from a recreational trawler coming out of a berth, I interpret it as "Hey everyone, look at me, look at me"

To me it means "look OUT for me."

 

[Lepke]

I'm 70. When I was young, I remember the ports were alive with whistles. Now I rarely hear them. Something has changed. I winter on the Columbia River. The only horns I hear are freighters clearing a dock or freighters in the fog. I don't think I've heard a tug horn even once a month.

 

[psneeld]

Radios and port controls.