Seafarers sailing on international waters often come across other ships coming from various locations. Belonging to various parts of the world, seafarers are bound to face communication barriers finding it difficult to communicate with each other. The International Maritime Organisation understood the challenge that maritime vessels face in communicating with each other and shore authorities while on a voyage. Due to the change in language from one place to another, seafarers find it challenging to convey messages; therefore, a need for a standardised method of communication arose. The international code of signals helps in seamless communication even during low visibility conditions during voyages. It is capable of both long and short-term communications. Let us learn more about applying the international code of signals in maritime. 

What is maritime signalling? 

Maritime signalling means communicating messages to other vessels during sailing or to people offshore. There are various systems and methods of maritime signalling to ensure the navigational safety of vessels during sailing and prevent any risks of accidents. It also helps vessels to become available for other ships in case of emergencies at sea. In simple words, during their voyage, vessels communicate with each other through various modes such as radio communication, hoisting flags or blowing whistles. The different types of containerships are large and require effective communication during their voyage or with the port authorities. Mobile networks do not work overseas; therefore, the maritime industry has adopted maritime signalling to establish seamless communication and avoid errors due to miscommunication. The national maritime signalling has devised different signals for different situations and emergencies that must be known by all seafarers for accessible communication. 

What is the International Code of Signals in IMO? 

All navigation-related matters at sea are communicated via signals and codes between sea vessels in the maritime industry. The INTERCO, or International Code of Signals and Codes, is a standardised system of signalling in maritime that is universally followed by all shipping lines in the global maritime industry. The environment at sea is quite unstable and full of turbulence. During the sailing, vessels may encounter challenging situations and require external aid. A standardised way of maritime communication helps establish an error-free and immediate means of getting timely help from the nearest port authorities or vessels. The British Board of Trade coined it and it is now followed by all for commercial shipping purposes. The INTERCO in the maritime industry effectively communicates long messages through shorter derivatives like Morse code or flag signalling, where every action holds a significant message. 

What is the importance of the International Code of Signals? 

The international code of signals must be understood and followed by all vessels involved in commercial shipping on international waters. It is to ensure the safety and standard sailing protocols to protect the vessels, cargo containers and seafarers. 

• It helps establish a standardised form of global communication, which helps mitigate the language barrier between vessels or port authorities from different parts of the world. 
• It ensures the safety of the crew and ship in case of any distress and prevents maritime accidents. 
• It is not limited to one form of communication, but there are various modes of signalling vessels and shore stations, including torches, flags, radio communication, whistles, etc. So, even if ships fail to communicate via one mode, they have plenty of other ways. 
• ICS, or International Code of Signals, ensures consistent interpretation of codes throughout the maritime industry anywhere across the globe to maintain the international standards of trade. 
• It facilitates vessels communicating emergency plans with each other if necessary if they cannot connect with the port authorities in case of maritime accidents or cybersecurity threats in maritime.

How does the International Code of Signals play a crucial role in the safe navigation of ships? 

The primary purpose of the International Code of Signals is to offer navigational security to large vessels during their voyage. Various seafarers on the ship use it. 

1. Crew members– The onboard crew mainly utilises the international code of signals to communicate with other vessels and convey their intentions to ensure safe navigation. Pilots are responsible for making decisions during emergencies. In such cases, pilots communicate through signals to ensure their recommendations are understood and followed. 
2. Vessel traffic service– These are centres located at huge ports or waterways that receive a heavy flow of vessels throughout the day. They help manage traffic flow and know the safety of vessels passing through the area. ICS facilitates seamless communication through signalling. 
3. Shore authorities– The port authorities and coastal guards need to be in contact with the offshore vessels to communicate navigational warnings, safety control measures or other changes regarding the course of routing. ICS is helpful in the transmission of such crucial information. 
4. Search and rescue organisation– The SAR comes to the aid of vessels in distress and needs to communicate effectively to know the current state, location and issue concerning the distress. ICS helps as a tool for providing active responses to any emergency or accident at sea. 

What are the various ways of signalling in maritime? 

1. Visual signalling– These are short-distance signals, generally communicated using flags, flashlights, and flareguns depending on day or night. These can either be distress signals, convey the vessel’s identity, or requests with other vessels. 
2. Sound signalling– In cases of dense fog and low visibility during voyages, vessels use horns and whistles to communicate route changes or alert other vessels of their presence. There are different frequencies and types of sounds to indicate additional messages. 
3. Radio signalling– It is one of the most significant forms through which vessels communicate with other vessels or shore stations. Vessels are equipped with VHF radios to facilitate long-distance transmission of data and communication with ships beyond the visual or audio range. 
4. Morse codes– Vessels have designed distress signals in the form of dots and dashes or encrypting messages using specific flags or codes that cannot be interpreted by any foreign party that intends harm to the vessel. 

What are Standard Maritime Communication Phrases? 

Nautical flags represent the standard phrases in maritime signalling, including 26 square nautical flags, each starting with a new alphabet and representing a new message. For example-  

• Alpha- “Diver down, keep clear.” 
• Bravo- ‘I am taking in, discharging, or carrying dangerous goods. ‘ 
• Charlie- “Yes” (confirmation).  
• Delta- “I’m manoeuvring with difficulty and require assistance.” 
• Whiskey- ‘I require medical assistance. ‘ 

Apart from this, there are ten numeral pennants from 0 to 9 that assist in easily identifying ships. It is used to distinguish between ships with the same or somewhat similar name or assist ship recognition among a fleet of ships belonging to the same class.  

These are the international code of signals and their uses across the maritime industry to signal vessels in the voyage and communicate with port authorities on shore. 

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