International Code of Signals

How to say "Communicate with me!" in nine languages.

The International Code of Signals is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp ("blinker"), flag semaphore, radiotelegraphy, and radiotelephony.

Standards

"The purpose of the International Code of Signals is to provide ways and means of communication in situations related essentially to safety of navigation and persons, especially when language difficulties arise." It has done this by first establishing a standardized alphabet (the letters A to Z, and the ten digits), along with a spoken form of each letter (to avoiding confusing similar sounding letters, such as 'b', 'p', and 'v'), and associating this alphabet with standardized flags. (See chart, right.)

Combinations of these alphanumeric characters are assigned as codes for various standardized messages. For instance, the master of a ship may wish to communicate with another ship, where his own radio may not be working, or the other ship's call sign is not known, or the other ship may not be maintaining a radio watch. One simply raises the Kilo flag (see diagram at the top), or sends the Morse code equivalent (dash-dot-dash) by flashing light; this has the assigned message of "I wish to communicate with you."

One of the elegant aspects of the ICS is that all of the standardized messages come in nine languages (English, French, Italian, German, Japanese, Spanish, Norwegian, and, since 1969, Russian and Greek). That the sender and receiver(s) are using different languages is immaterial; each language has a book with equivalent messages keyed to the same code. This is also useful in radiotelephony, or even when ships are within hailing distance, if there is no common language: a crewman on a burning ship yells "yuliett alfa vour", and a vessel coming to their aid knows exactly what they need: "material for foam fire extinguishers" (that is, the foaming agent). (See de:Flaggenalphabet for the German version of single-letter signals.)

The Code also covers procedural aspects (how to initiate a call, the format of a message, how to format date and time, etc.), how naval ships (which usually use their own codes) indicate they are using the ISC (by flying the Code pennant), use in radiotelephony (use of the spoken word "Interco"), and various other matters (such as how an aircraft directs a vessel to another vessel in distress, and how to order unidentified submarines to surface).

Signals

Prior to 1969 the Code was much more extensive, covering a wider range of messages, and included a list of five letter codes for every prominent maritime location in the world. Since 1969 it has been reduced to focus on navigation and safety, including a medical section. Signals can be sorted into three groups:

• Single-letter signals which are very urgent, important, or common.
• Two-letter signals for other messages, sometimes followed with a numeric "complement" that supplements or modifies the message.
• Three-letter signals beginning with "M" – these are the Medical Signal Codes.

Sample Single Letter Messages
Flag Hoist	Code	Meaning
	A	I have a diver down; keep well clear at slow speed.
	B	I am carrying or discharging dangerous goods.
	H	I have a pilot on board.

In some cases additional characters are added to indicate quantities, bearing, course, distance, date, time, latitude, or longitude. There is also provision for spelling words, and for indicating use of other codes.

Several of the more common single-letter signals are shown at the right. Two-letter signals cover a broad gamut of situations; the interested reader is urged to download a copy of the Code from the link below.

Repeated characters can be a problem in flaghoist. To avoid having to carry multiple sets of signal flags, the Code uses three "substitute" (or "repeater") flags. These repeat the the flag at the indicated position. For instance, to signal MAA ("I request urgent medical advice", see diagram below) the Mike, Alfa, and 2nd substitute flags would be flown, the substitute indicating a repeat of the second character.

Medical Signal Code

A hoist of three flags
Flag Hoist	Code	Meaning
	MAA	I request urgent medical advice.
the pennant at the bottom indicating to repeat the second letter

The Medical Signal Code (incorporated in the International Code of Signals since 1930) is a set of codes for describing medical cases and recommended treatments. While plain language is preferred in such cases (presumably via radio), even where there are no language problems the Medical Signal Code is still provides a standard method of case description and treatment. Parts of the body, types of symptoms, treatments, even a list of standard medicines, all have been carefully cataloged and numbered, so a great deal of information can be precisely and succinctly communicated. Certain medicines also a carry warning to confirm by radiotelephone, to guard against communication errors.

History

The first International Code of Signals was drafted in 1855 by the British Board of Trade and published by the Board in 1857 as the Commercial Code. It came in two parts: the first containing universal and international signals, and the second British signals only. Eighteen separate signal flags (see chart) were used to make over 70,000 possible messages (vowels were omitted from the set to eliminate the possibility of spelling obscenities, and some little-used letters were also omitted). It was revised by the British Board of Trade in 1887, and was modified at the International Conference of 1889 in Washington, D.C. The code was used at the Battle of Tsushima, when the survivors of the Russian fleet sent XGE ("I surrender"), to the astonishment of the Japanese officers.^{[citation needed]}

After World War I, The International Radiotelegraph Conference at Washington in 1927 considered proposals for a new revision of the Code. The Code was prepared in seven languages: English, French, Italian, German, Japanese, Spanish and in Norwegian. This new edition was completed in 1930 and was adopted by the International Radiotelegraph Conference held in Madrid in 1932. The Madrid Conference also set up a standing committee for continual revision of the Code.^{[citation needed]}

The new version introduced vocabulary for aviation and a complete medical section with the assistance and by the advice of the Office International d’Hygiene Publique. A certain number of signals were also inserted for communications between vessels and shipowners, agents, repair yards, and other maritime stakeholders.

After World War II, The Administrative Radio Conference of the International Telecommunication Union suggested in 1947 that the International Code of Signals should fall within the competence of the Inter-Governmental Maritime Consultative Organization (IMCO), which became the IMO. In January 1959, the First Assembly of IMCO decided that the Organization should assume all the functions then being performed by the Standing Committee of the International Code of Signals.

The Second Assembly of IMCO 1961 endorsed plans for a comprehensive review of the International Code of Signals to meet updated requirements of mariners. The revisions were prepared in nine languages: English, French, Italian, German, Japanese, Spanish, and Norwegian, Russian and Greek.

The Code was revised in 1964 taking into account recommendations from the 1960 Conference on Safety of Life at Sea (SOLAS) and the 1959 Administrative Radio Conference, in Geneva 1959. It was adopted in 1965.

Every signal in the INTERCO has a complete meaning; that is, a recipient does not need to receive two or more signals to complete a message.

The International Code of Signals is currently maintained by the International Maritime Organization.

The English-language version of the Code is available through the National Geospatial-Intelligence Agency (NGA), which was formerly the National Imagery and Mapping Agency, as Publication 102.^[1]

See also

Nautical portal

Wikimedia Commons has media related to: International Code of Signals

• Excerpt from Brown's Signalling (1916), showing earlier version of ICS.
• Flaghoist signalling
• Maritime flag signalling
• International maritime signal flags
• Spelling alphabet
• NATO phonetic alphabet

References

All material in this article, unless explicitly cited elsewhere, is from:

1. ^ International Code of Signals, United States Edition (Revised 2003)

External links

• Freeware program teaches & translates ICS Flags

Examples

Sample International Code of Signals Messages
Flag Hoist	Code	Meaning
	AC	I am abandoning my vessel.
	AD	I am abandoning my vessel which has suffered a nuclear accident and is a possible source of radiation danger.
	AN	I need a doctor.
	AN 1	I need a doctor; I have severe burns.
	AN 2	I need a doctor; I have radiation casualties.
	EL	Repeat the distress position.
	EL 1	What is the position of vessel in distress?
	GM	I cannot save my vessel.
	GN	You should take off persons.
	GN 1	I wish some persons taken off. Skeleton crew will remain on board.
	GN 2	I will take off persons.
	GN 3	Can you take off persons?
	IT	I am on fire.
	MAA	I request urgent medical advice.
	MAB	I request you to make rendezvous in position indicated.
	MAC	I request you to arrange hospital admission.
	MAD	I am . . . (indicate number) hours from the nearest port.
	MS 1	My vessel is a dangerous source of radiation; you may approach from my starboard side.
	VG	The coverage of low clouds is… (number of octants or eighths of sky covered).
	US 4	Nothing can be done until weather moderates.