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Introduction

The International Maritime Organization (IMO) was established in 1959 and have since then tried to enhance the radio-communication in relation to the International Convention for the Safety of Life at Sea (SOLAS) (GMDSS Manual, 2019). In addition, IMO cooperates closely with the International Telecommunication Union (UTI) and other international organizations to improve maritime communication. Consequently, due to their work, the implementation of the Global Maritime Distress and Safety System (GMDSS) transpired in 1999 (GMDSS Manual, 2019).

In simple terms, the GMDSS exists to ensure that a vessel in distress can alert search and rescue authorities on land and other ships in close vicinity. However, a GMDSS-system also exists to enable maritime safety information (MSI), weather information, navigational warnings, and different types of radio communication, e.g., safety and urgency, etc. (GMDSS Manual, 2019).

A ship must have the ability to communicate in any of the mentioned ways,

independently of where it operates. However, as various communication systems can operate within different ranges, different types of systems are used depending on where the ship operates. Within the GMDSS, we divide the ocean into different “Sea Areas,” depending on which systems you can use within the areas. There are four areas, i.e., Sea Area 1,2,3, and 4. We will provide you with more information about these areas in chapter 2. Also, the GMDSS comprises two main ways of communication, i.e., Satellite communication versus Terrestrial communication.

GMDSS Communication. © TERP.

The terrestrial communication system is radiotelephony communication systems with Digital Selective Calling (DSC).

DSC means that the radio operator can transmit and receive a digital distress or safety message from a radio station on land or a ship. Also, some of the terrestrial systems have a function enabling the operator to communicate via written messages, instead of general voice radiotelephony. This type of function is called the Narrow Band Direct Printing (NBDP).

You can divide the terrestrial communication into the following types of ranges:

The satellite communication system is dependent on a satellite to transmit the communication between two radio stations, e.g., a ship station and a land station. There are three satellite systems used within the maritime communication systems;

You can use the satellite systems in areas where the range of the terrestrial systems might not reach land. Therefore, satellite systems exist to ensure that ships can send a distress message to a land station even when the vessel operates in an area where terrestrial communication systems do not work, i.e., does not reach land.

Terrestrial and Satellite communication. © TERP.

The statutory framework of the Maritime Mobile Service

.

International Convention of Safety of Life at Sea

The development of the Safety of Life at Sea (SOLAS) convention occurred due to the terrible accident on Titanic in the year 1914. The SOLAS convention contains eleven chapters that comprise designated regulations to prevent accidents from happening out at sea.

SOLAS Chapter IV comprises radiocommunication and states the requirements and regulations regarding ships using radiocommunication. According to SOLAS Chapter IV, regulation 4 “Functional requirements” all ships out at sea must be able to;

Receive:

Transmit and receive;

According to regulation 7, “Radio equipment: General” in SOLAS chapter IV,

all ships following the GMDSS-convention, must have the following radio equipment:

In addition, all passenger ships must have search and rescue radio equipment on the aeronautical frequencies; 121.5 MHz, and 123.1 MHz (SOLAS, 2014).

As mentioned earlier, there are four Sea Areas, i.e., Sea Area 1,2,3, and 4. The four sea areas exist to ensure that ships can always communicate and send distress alerts to land stations. The areas are located from a short-range to a long-range distance from land and require different types of instruments to ensure ship-to-shore communication. You can find the requirements to ensure such communication in SOLAS Chapter IV and the GMDSS manual.

Sea Area 1; is typically located approximately 20-30 miles from land within the range of minimum one VHF coast station with continuous DSC alerting. All ships in Sea Area 1 must be able to transmit ship-to-shore distress alerts on minimum one of the following types of equipment: VHF with DSC alerting, EPIRB (406 MHz), MF with DSC alerting, HF with DSC alerting, or through an INMARSAT system. However, the most commonly used equipment in Sea Area 1 is the VHF DSC,

as the area is so close to land.

Sea Area 2; is located outside of Sea Area 1, approximately 100 miles from land. Sea Area 2 is within range of minimum one MF coast station with continuous DSC altering. According to SOLAS ship’s requirements, all ships following the GMDSS convention operating within Sea Area 2 shall have an MF radio which is capable of transmitting and receiving distress and safety communication on DSC (2187,5 KHz) and regular radio communication (2182 KHz).

MF Frequencies
MF DSC frequency = 2187,5 KHz

MF Radio communication frequency = 2182 KHz

Ships operating within Sea Area 2 shall also be equipped with radio equipment, which has a continuous DSC watch. In addition to the MF radio, ships shall have at least one more type of radio equipment which can transmit ship-to-shore distress alerts., e.g., EPIRB,

HF with DSC, or an INMARSAT system (SOLAS, 2014).

Sea Area 3; is located outside of Sea Area 1&2 and is located approximately between 70º N and 70º S. Sea Area 3 is within the range of the Inmarsat satellite communication system with continuous alerting. According to SOLAS ship’s requirements, all ships following the GMDSS convention operating within Sea Area 3 shall have the equipment identified in alternative 1 or 2.

Example 1. An Inmarsat ship earth station that can transmit and receive distress and safety messages, send and receive distress calls, and regular radio communication, either as a message or through regular radiotelephony. The Inmarsat ship earth station must also be able to keep watch for ship-to-shore distress alerts. The ship must also have an MF radio designated for safety and distress purposes using both DSC and regular radio communication and radio equipment, which can keep a continuous DSC watch on 2187.5 KHz (MF). Also, ships within Sea Area 2 shall have radio equipment that can transmit ship-to-shore distress alerts, e.g., EPIRB, HF with DSC, or via the INMARSAT system.

Example 2.

An MF/HF radio which can transmit or receive distress and safety messages with the following:

The ship must also have radio equipment that can keep a DSC watch on frequencies used in Sea Area 3 and a radio system other than HF, which can transmit a ship-to-shore distress alert, i.e., an EPIRB or an INMARSAT system. Ships in Sea Area 3 should also have an MF/HF system transmitting and receiving regular radio communication on radiotelephony or direct printing telegraphy (SOLAS, 2014).

Sea Area 4; is the remaining sea area outside of Sea areas 1,2, and 3. Sea Area 4 is, therefore, also the sea area around the North Pole. According to SOLAS ship’s requirements, all ships following the GMDSS convention operating within Sea Area 4 shall have the same equipment as described in Sea Area 1,2, and 3. However, as you can see in Sea Area 3, “the ship shall have a radio system other than HF, which can transmit a ship-to-shore distress alert, i.e., an EPIRB or an INMARSAT system.” In Sea Area 4, the ship must have both an EPIRB AND an INMARSAT system. This is to ensure that the ships operating in Sea Area 4 can send a distress message to shore, as the coverage for the INMARSAT satellites and the EPIRB may vary in this area.

All ships must ensure a continuous watch on the designated DSC channels/frequencies depending on the Sea Area the ship operates in, e.g., DSC channel 70 (VHF), DSC frequency 2187.5 (MF) or DSC frequency 16804.5 (HF), etc. Also, if the ship has an Inmarsat ship earth station, the ship must ensure a continuous DSC watch on ship-to-shore distress alerts. All ships shall also keep watch on relevant frequencies for maritime safety information (MSI) broadcasts (SOLAS, 2014).

The ship's main power system must have enough power to supply the radio-installations available onboard. Also, an independent redundant power source shall exist on all ships, enabling the radio installation to run even if the main power shuts down. The radio equipment can run 1 hour on emergency power systems or 6 hours on the ship's redundant power source if the main power shuts down (SOLAS, 2014).

Radio Regulations

The International Telecommunication Union (ITU) is the united nations agency specialized within communication and information technology. ITU (founded in 1865) focus on improving and enhancing communication all over the world. For instance, when you call a friend or a family member on your mobile phone, you are ultimately taking part in a network ITU helped develop. The ITU published “Radio Regulations” (Volume 1-4) in 1995, to ensure a global standardized radio communication. In addition, the ITU has developed a maritime mobile service (MMS) to provide communication between ship stations, coast stations to ship stations, etc. The ITU has developed a “Manual for Use by the Maritime Mobile and Maritime Mobile-Satellite Services”; however, the “Radio Regulations” (Volume 1-4) also covers the MMS regulations.

When you are out sailing and want to come in contact with another vessel, the most rapid and easy way is through the ship's radio station. The master of the ship is in charge of the radio station and must ensure that all radio operators onboard comply with the Radio Regulations given by the ITU.

In other words, the master must ensure that the radio operators have the proper training and hold the necessary certificates and knowledge required to use the radio station.

Also, a transmitting radio station must have a license. The license is issued by or on behalf of the country where the radio station is registered. Consequently, a ship's radio station is commonly registered in the same country as the ship itself. A radio station license shall include the radio station's name, its call sign, the particulars for the specific radio station, and some of the installation characteristics. The master and radio operators must be ready for an inspection of the radio station. Such inspections are conducted to ensure that the station is maintained and in agreement with the issued license. Also, such an inspection can include a review of the radio operators' certificates. Before leaving the ship, the inspector must report the results to the master of the ship. The frequency of radio inspections depends on the ship's flag state, classification, and other governmental regulatory the ship is subjected to.

All radio operators’ on board ships, which must follow to the global maritime distress and safety system (GMDSS),

shall carry a radio operator certificate issued by the government or country which the radio station, i.e., the ship, is registered in. Such certificates issued after 1 January 1978 shall include the following information:

Ref: Radio Regulations Article 47 (ITU 2012)

The certificate shall also hold the operator’s signature and the signature from one designated person from the administration issuing the certificate. This is to reduce the risk of false certificates. Also, a maritime radio certificate issued after 1 January 1978 shall hold a photo of the operator.

However, according to the ITU, the radio operator must only hold such a certificate if the radio station is operating on frequencies above 30 MHz. If the radio station operates above 30 MHz, it is up to each government to decide and define the required certificate (Radio Regulations Article 47 (ITU, 2012).

There are two types of operator certificates that meet the GMDSS requirements within the commercial shipping industry. The documents are as follows;

The ROC certificate is restricted to radio-equipment that you use in Sea Area 1,

while the GOC is a general certificate and is applicable for all Sea Areas 1-4, all over the world.

The radio operator must be minimum 18 years old to receive a GOC/ROC – certificate, and the exam consists of two parts; one written and one practical exam. You must renew the certificate every fifth year and ensure that you have enough seagoing time (1 year of seagoing time within the last 5 years) to renew the certificate. If you don’t have enough seagoing time to renew the certificate, you can take a renewal course and renew the certificate after that.

Frequency is defined as the number of times something occurs over a designated time period.

Frequency
Nr of times something happens / Time period

The word frequency is related to the word frequent, meaning that if something happens frequently, it gives you a frequency. For example, if you turn on and off the light in your classroom several times,

that gives you a frequency. You measure Frequency in Hertz, which you define as; the number of times something happens in 1 second.

Hertz (Hz)
Nr of times / 1 Second

Consequently, if you turn on and off the light in your classroom twice within 1 second, that will give you a frequency of 2 Hertz.

Within radio communication, we talk about radio frequencies, which are the radio waves oscillating alternations within a period of time. Radio frequencies are normally given in kHz, MHz, or GHz. When you communicate on any radio equipment, you transmit electric magnetic waves, also called radio waves. Various types of equipment transmit various types of radio waves, which means that the frequencies differ depending on the equipment you use.

As mentioned before, ITU´s maritime mobile service (MMS) ensures the maritime radio communication. The frequencies that you use within the maritime mobile service (MMS) are divided into 8 frequency bands.

MMS Frequency Bands

VLF – Very low frequencies 3 – 30 kHz

LF – Low frequencies 30 – 300 kHz

MF – Medium frequencies 300 – 3 000 kHz

HF – High frequencies 3 – 30 MHz

VHF – Very high frequencies 30 – 300 MHz

UHF – Ultra high frequencies 300 – 3 000 MHz

SHF – Super high frequencies 3 – 30 GHz

EHF – Extra high frequencies 30 – 300 GHz

VLF – Very low frequencies 3 – 30 kHz

LF – Low frequencies 30 – 300 kHz

MF – Medium frequencies 300 – 3 000 kHz

HF – High frequencies 3 – 30 MHz

VHF – Very high frequencies 30 – 300 MHz

UHF – Ultra high frequencies 300 – 3 000 MHz

SHF – Super high frequencies 3 – 30 GHz

EHF – Extra high frequencies 30 – 300 GHz

These bands and usages are defined by ITU and are shown in figure x.

By interference,

we mean everything that can disturb a transmission or a frequency. For example, interference can occur by human interaction as an operator transmits on a radio station which s/he is not supposed to transmit on. It is of great importance not to interfere with an ongoing radio call or message, especially on the distress frequencies.

One must also test and approve electrical devices and other types of equipment installed onboard the ship in relation to the GMDSS-equipment, to ensure that the devices do not cause any interference with the radio equipment onboard the ship. To reduce harmful interference, there are international monitoring where governments and countries develop monitoring facilities where administrations or countries work together.

There are three main modes of communication within the maritime radio communication systems:

The most common way to communicate is through radiotelephone communication where you transmit audio signals (i.e., your voice from when you speak into the radio) via a radio frequency. The transmitted audio signal is then received and amplified in the receiving radio stations loudspeaker.

We will explain this further and more detailed in chapter 5.

Digital selective calling (DSC) is a digital pre-defined message which you send via a radio link between two radio stations with DSC. You typically use DSC on VHF, MF and HF frequencies for distress, urgency, and safety alerts.

The narrow-band direct printing or radio telex, as its also called, is a type of message communication where you transmit written messages instead of audio signals by voice messages. You typically use NBDP on MF and HF frequencies for distress and safety alerts, including maritime safety information (MSI).

The High Frequency (HF) enables long-range radio communication for both ship-to-ship and shore-to-ship communication. There are designated HF frequency bands that secure HF communication. These bands are the 4,6,8,12 and 16 MHz. In areas where no satellite communication is available, e.g., some parts of Sea Area 4, HF communication is the only way to contact other ships or coast stations.

When you communicate on a VHF, it is important to remember that the misuse of communication on certain channels can cause interference and thereby jeopardize the safety at sea.

To avoid such interference, it is of great importance to ensure that the radio operator has the proper training and holds the necessary certificates required.

VHF Frequency band

The VHF frequency band is between 30 MHz – 300 MHz.

The VHF frequency band is between 30 MHz – 300 MHz.

If you want to transmit a message over the VHF, you must first think thoroughly through what you wish to communicate and what words to use. If necessary, you can prepare some notes, for example, if you have to remember a specific position or a loading status, etc. Before you transmit the message over the VHF, it is also important to make sure that the channel you wish to operate on is available to avoid interference.

When you communicate over VHF it is also important to avoid calling on channel 16 if not necessary, e.g., during distress, urgency, and safety calls or when contacting another vessel.

However, when you contact another vessel, it is of great importance only to occupy channel 16 in the shortest amount of time possible and thereby change to another working channel as soon as you have established contact. Also, you should not use any offensive language during any radio operation.

The VHF system is also a life-saving appliance, and it is therefore mandatory to have minimum three portable VHF radiotelephones on passenger and cargo ships with a size of 500 gross tonnage and above. Cargo ships with a size of 300 gross tonnages up to 500 gross tonnages must have minimum two portable VHF radiotelephones. This is to ensure that you can bring the VHF-radio with you into, e.g., a life raft if you have to abandon the ship.

When you communicate with a coast station, you are only to discuss operational or safety-related matters. If a coast station contacts your vessel, they typically call on VHF channel 16. When you have answered the call on channel 16, a change of channel is required. After you have replied to the coast station on channel 16, they will suggest a change of channel and give you a designated channel number, which you must confirm and change to. You change the channel since it’s not allowed to interfere with the distress frequencies longer than necessary.

If you are the one contacting a coast station on VHF channel 16, you must be the one to suggest a change of channel and thereby give the coast station a designated working channel which they can change to.

When you communicate bridge-to-bridge, you can, in theory, discuss anything which you find important. However, it is essential not to occupy a working channel for too long as other ships might require the channel to communicate as well. If you want to contact another ship on VHF, you must first establish contact on channel 16 and then change to a working channel to avoid interfering on the distress channel for too long.

Example of ship-to-ship calling:

The vessel Viking Poseidon calls Ramform Titan:

Viking Poseidon:

Ramform Titan this is Viking Poseidon, Viking Poseidon on channel 16

Ramform Titan:

Viking Poseidon this is Ramform Titan on channel 16

Viking Poseidon:

Good evening Ramform Titan, please come to working channel 6

Ramform Titan:

Copy that, changing to working channel 6

Example of ship-to-ship calling:

The vessel Viking Poseidon calls Ramform Titan:

Viking Poseidon:

Ramform Titan this is Viking Poseidon, Viking Poseidon on channel 16

Ramform Titan:

Viking Poseidon this is Ramform Titan on channel 16

Viking Poseidon:

Good evening Ramform Titan, please come to working channel 6

Ramform Titan:

Copy that,

changing to working channel 6

Within the maritime mobile service and the maritime mobile-satellite service, there are four levels of call priorities which a maritime radio station must offer. The four levels of communication are as follows:

1.Distress

2.Urgency

3.Safety

4.Other/Routine

Typically, if you use a terrestrial communication system during distress, urgency, or a safety alert, a DSC announcement is first transmitted, followed by a call and message transmitted using the radiotelephony (GMDSS-Manual, 2019).

Distress communication has priority over all other transmissions. You transmit distress communication on designated distress frequencies on radiotelephony, DSC, or via satellite communication. Sending a distress call or message on, e.g., the DSC, implies that the mobile unit, e.g., the ship, or person, e.g., a crew-member, is in serious or imminent danger and requires help immediately.

Distress Frequencies

VHF

Radiotelephony (Channel 16) 156.8 MHz

DSC (Channel 70) 156.525 MHz

MF
Radiotelephony 2182 kHz

DSC 2187.5 kHz

NBDP 2174.5 kHz


HF

Radiotelephony 4125 kHz, 6215 kHz, 8291 kHz, 12290 kHz, 16420 kHz

DSC 4207.5 kHz, 6312.0 kHz, 8414.5 kHz, 12577.0 kHz, 16804.5 kHz

NBDP 4177.5 kHz, 6268.0 kHz, 8376.5 kHz, 12520.0 kHz, 16695.0 kHz

VHF

Radiotelephony (Channel 16) 156.8 MHz

DSC (Channel 70) 156.525 MHz

MF
Radiotelephony 2182 kHz

DSC 2187.5 kHz

NBDP 2174.5 kHz

HF

Radiotelephony 4125 kHz,

6215 kHz, 8291 kHz, 12290 kHz, 16420 kHz

DSC 4207.5 kHz, 6312.0 kHz, 8414.5 kHz, 12577.0 kHz, 16804.5 kHz

NBDP 4177.5 kHz, 6268.0 kHz, 8376.5 kHz, 12520.0 kHz, 16695.0 kHz

The distress alert shall contain the following information:

MAYDAY MAYDAY MAYDAY

This is:

Ships name – ships name – ships name

CALL SIGN

MMSI Number (Only if the first distress alert was sent by DSC)

IN POSITION (longitude and latitude)

NATURE of the distress

The required type of ASSISTANCE

Additional INFORMATION of importance (E.g., number of persons onboard)

(GMDSS Manual, 2019).

MAYDAY MAYDAY MAYDAY

This is:

Ships name – ships name – ships name

CALL SIGN

MMSI Number (Only if the first distress alert was sent by DSC)

IN POSITION (longitude and latitude)

NATURE of the distress

The required type of ASSISTANCE

Additional INFORMATION of importance (E.g.,

number of persons onboard)

(GMDSS Manual, 2019).

Urgency communication has the second priority after a distress alert. If a vessel sends out an urgency alert, the vessel or the persons onboard are not in immediate danger, but the situation is still hazardous, and help is required.

The frequency you use for urgency communication is the same as the distress frequencies stated above in the Distress section.

The urgency alert shall contain the following information:

PAN PAN PAN PAN PAN PAN

All stations, all stations, all stations

This is:

Ships name – ships name – ships name

CALL SIGN

MMSI Number (Only if the first distress alert was sent by DSC)
POSITION

The NATURE of the urgency

(GMDSS Manual, 2019).

PAN PAN PAN PAN PAN PAN

All stations,

all stations, all stations

This is:

Ships name – ships name – ships name

CALL SIGN

MMSI Number (Only if the first distress alert was sent by DSC)
POSITION

The NATURE of the urgency

(GMDSS Manual, 2019).

A safety message is typically sent out by a coast station or a vessel that wants to communicate any relevant information, e.g., meteorological or navigational warnings. Before the actual safety message is sent out on a designated working channel, a short message is sent out on the distress frequencies, e.g., channel 16. The short message informs that a safety message will be given on the region's working channel. After the short message on channel 16, the safety message is given on the designated working channel. Every region has their designated working channels for safety messages and routine calls.

The safety message shall contain the following information:

SECURITE, SECURITE, SECURITE

All stations, all stations, all stations

This is:

Ships name – ships name – ships name

CALL SIGN

MMSI Number (Only if the first distress alert was sent by DSC)
POSITION

The designated safety information



(GMDSS Manual, 2019).



SECURITE, SECURITE, SECURITE

All stations, all stations, all stations

This is:

Ships name – ships name – ships name

CALL SIGN

MMSI Number (Only if the first distress alert was sent by DSC)
POSITION



(GMDSS Manual, 2019).

All other types of routine radio communication have the lowest priority as this type of communication does not contain any immediate danger for the ship or the crew itself.

You use designated working channels for such communication. However, to establish contact with, e.g., another vessel, you must first call the vessel on a distress frequency, e.g., channel 16, to get the vessel's attention.

You contact another ship or a coast station over the radio as follows:

Stations name

This is:

Ships name, ships name

On channel 16

Stations name

This is:

Ships name, ships name

On channel 16

When you have established contact with the desired station, you can change to a working channel by asking the ship or coast station to change to a designated working channel. This is important so that you don’t disturb the distress or urgency communication.

If you don’t know the name of the vessel you would like to come in contact with,

you can use the vessels position instead of the name:

Vessel in position: Longitude Latitude (repeat the position at least once)

This is:

Ships name, ships name

On channel 16

[quiz_group id="233"]

 

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