SOUND SIGNALS

by

Jeremy R. Hood

One of the best free trips I have come across is taking the ferry from Galveston to the Bolivar Peninsula. You get a ride on the bay crossing the ship channel and even this short passage captures a similar excitement of a landfall that I experience when making offshore passages. And have you noticed that every time the ferry leaves her dock she sounds one long blast. Do you know what it means? Maybe a ship entering the Galveston jetties sounds one short blast. what does this mean? Making sound signals from a small boat is often of little practical use but knowing the meaning of the signals made by large commercial vessels is important for only when you understand what they mean can you manoeuvre correctly and safely. I am sure that when you were last in a large port you heard plenty of these but, not understanding their specific meanings, you probably dismissed them as one does the whistles of a freight train.

Table I: SOUND SIGNALLING EQUIPMENT REQUIRED BY THE RULES

Length of vessel less than 12 (39) 12 (39) - 100 (328) more than 100 (328)

in meters (feet)

 

Whistle  x*  x  x  

Bell     x x

Gong       x

 

*vessels under 12 meters(approx 39 feet) are not obliged to have a whistle but if they do not they shall have some other means of making an efficient sound signal. See rule 33 of the Navigation Rules for more information.

 

 

Sound signals are used in both normal and restricted visibility. In normal visibility they indicate what manoeuvre a vessel is doing (or intending to do) while in fog or reduced visibility the sound signals are used to indicate the type of vessel. A long blast will last from 4-6 seconds while a short blast will be about 1 second long. Though most vessels will use a horn to make most of their sound signals the rules refer only to a whistle.

 

Have you ever taken the intercoastal along the Texas coast? It is a neat trip passing great expanses of water and then moments later constrained by the banks of a winding canal. Wildlife enthusiasts are sure to enjoy it and for an Englishman unused to seeing wild animals larger than a fox it can be a great experience: on my last trip up from Corpus I saw a wild boar at the waters edge. Well if you have taken this trip you are sure to have passed a number of barges being pushed along the waterway. And if you have spoken with them on the radio or even listened to the bargees talking with each other you will have heard comments such as pass me on the one whistle. This is an alternative (and somewhat abbreviated) form of the communication required on Inland waters. Understanding the sound signals that are required in these circumstances will help you to understand what is being agreed to on the radio.

Table II: SOUND SIGNALS USED IN NORMAL VISIBILITY

Sound signal International rules   Inland rules*

 

_   Altering course to starboard  Intends to alter course to starboard**

_   _ Altering course to port  Intends to alter course to port**

_   _   _ Operating astern propulsion  Operating astern propulsion

              _______ Approaching a bend in a channel Approaching a bend in a channel and leaving a dock or berth

 

    * Sound signals are used in areas covered by the inland rules when vessels are in sight of one another and meeting or crossing at a distance of within half a mile of each other (rule 34)

    ** Confirmation is required from the approaching vessel before the manoeuvre may be made

 

While this table is correct not all of the sound signals allowed by the rules are covered. See rule 34 for more information.

 

When making offshore passages it is rare to hear sound signals used though there is one instance when it can be extremely helpful. Perhaps one of the most unnerving potential collision situations when you are on a small boat is where a large freighter is approaching from astern. The rules make it clear that in these circumstances the overtaking vessel has to keep clear but how do you, in your small boat ever know you have been seen until the vessel changes course. I can recall a number of instances when I have been worried by a large ship approaching in this way. The first was in the English Channel when I was sailing alone and just had to hold my course until the ship did eventually alter course. A more recent incident occurred last year, at night when north of Jamaica, and we were at the point of using a search light towards the ship and I had a white collision avoidance flare ready to use. I don't think we had been seen until we used the spotlight as the vessel made a sudden move to avoid us. But the easiest situation of this type occurred when a cruise liner was approaching from astern early one morning in the Northwest Bahama Channel. A short blast on the ships whistle told us clearly that we had been seen and that she was altering course to starboard. But don't think you have to be far from Texas to experience these situations. I have heard sound signals used appropriately in the anchorage areas offshore from both Galveston and Port Aransas.

One of the most difficult times at sea can be when caught out in fog especially when surrounded by large vessels. Ideally it will be best to get in to shallow water where you can anchor relatively safely but getting there can sometimes be quite exciting. Last winter arriving off  Galveston at the end of an atlantic crossing we found ourselves in thick fog. Having a good crew and the right equipment enabled us to plan an entry through the jetties in these conditions. However our first attempt to locate a buoy well out from the entrance caused me considerable anxiety as when we arrived at what should have been the buoy we found the tall sides of a huge freighter looming out of the fog. After I had turned to head for safer water we recalculated our course and found our landfall buoy on the second occasion and then, as we made our way carefully in towards the Galveston Yacht Basin we heard all around us the moaning fog signals of the many ships. Knowing what the signals mean isn't all that helpful but in these circumstances it is better than nothing!

Table III:SOUND SIGNALS USED IN RESTRICTED VISIBILITY

Sound signal   Used by:

 

    ____   Power driven vessels under way and making way

____   ____   Power driven vessels under way but not making way

          ____   _   _   Vessels not under command, restricted in ability to manoeuvre, fishing, sailing

 

Though these sound signals are correct this is not a complete list of the signals used in restricted visibility. For full details see the Navigation Rules, rule 35

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