International Maritime Regulations

Important Abbreviations used in maritime regulations

IMO = International Maritime Organization

IMSO = International Maritime Satellite Organization

USCG = U.S. Coast Guard

SOLAS = Safety of Life at Sea

SSAS = Ship Security Alert System

ISPS = International Ship & Port Facility Security Code

MSR = Maritime Search and Rescue

MSC = Maritime Safety Committee

SAR = Search And Rescue

COMSAR = Sub-Committee on Radio communications and Search and Rescue

NMFS = National Marine Fisheries Service

VMS = Vessel Monitoring System

GMDSS = Global Maritime Distress & Safety System

EPIRB = Emergency Position Indicating Radio Beacon

NAVTEX = an international, automated system for instantly distributing maritime navigational warnings, weather forecasts and warnings, search and rescue notices and similar information to ships.

COSPAS-SARSAT = an international satellite-based search and rescue system, established by Canada, France, the USA, and Russia.

NOAA = National Oceanic Atmospheric Administration

SART = Search and Rescue Radar Transponder

DSC = Digital Selective Calling

AIS = Automatic Identification System

ITU = International Telecommunication Union

AMVER = Atlantic Merchant Vessel Emergency Reporting

International Maritime Regulations

The International Maritime Organization (IMO) is a specialized agency of the United Nations which is responsible for measures to improve the safety of international shipping and to prevent marine pollution from ships. It currently has 163 Member States. IMO was established to adopt legislation. Governments are responsible for implementing it.

The SOLAS Convention in its successive forms is generally regarded as the most important of all international treaties concerning the safety of merchant ships. The first version was adopted in 1914, in response to the Titanic disaster, the second in 1929, the third in 1948 and the fourth in 1960. The 1960 Convention - which was adopted on 17 June 1960 and entered into force on 26 May 1965 - was the first major task for IMO after the Organization's creation and it represented a considerable step forward in modernizing maritime regulations and in keeping pace with technical developments in the shipping industry.

The International Maritime Organization's ISPS Code has introduced new maritime regulations to protect ports and international shipping against terrorism, by improving early detection and monitoring of potential threats. All ships over 500 gross tones are required to be equipped with a Ship Security Alert System (SSAS), which is capable of discreetly raising the alarm to the relevant authorities and tracking the vessel if the security of the vessel is compromised. Compliance with this code will become mandatory in July 2004.

The Global Maritime Distress and Safety System (GMDSS) is an integrated communications system using satellite and terrestrial radio-communications to ensure that no matter where a ship is in distress, aid can be dispatched. Under the GMDSS, all passenger ships, carrying more than twelve passengers, and all cargo ships over 300 gross tonnage on international voyages have to carry specified satellite and radio-communications equipment, for sending and receiving distress alerts and maritime safety information, and for general communications. The GMDSS became fully effective from 1 February 1999.

What equipment is necessary under the GMDSS rules?

The exact suite of equipment depends upon the intended routes of your ship. A careful review of the new regulations is needed to determine the requirements applicable to each ship. A ship can sail in any of four sea areas, as defined below:
-Sea area A1. An area within the radiotelephone coverage of at least one VHF coast station in which continuous DSC alerting is available as defined by the International Maritime Organization.
-Sea Area A2. An area, excluding sea area A1, within the radiotelephone coverage of at least one MF coast station in which continuous DSC alerting is available as defined by the International Maritime Organization.
-Sea Area A3. An area, excluding sea areas A1 and A2, within the coverage of an INMARSAT geostationary satellite in which continuous alerting is available.
-Sea Area A4. An area outside sea areas A1, A2, and A3.

Is there any equipment that is common to all GMDSS ships?

Generally, all GMDSS ships carry a 406 MHz EPIRB, a VHF radio capable of transmitting and receiving DSC and radiotelephony, a NAVTEX receiver, a SART, and two-way VHF portable radios.

The satellite emergency position-indicating radio beacon (EPIRB), an element of the GMDSS designed to operate with COSPAS-SARSAT system. These automatic-activating EPIRBs, now required on SOLAS ships, commercial fishing vessels, and other ships, are designed to transmit to a rescue coordination center a vessel identification and an accurate location of the vessel from anywhere in the world.

A small, low-cost and self-contained "smart" printing NAVTEX radio receiver installed in the pilot house of a ship or boat checks each incoming message to see if it has been received during an earlier transmission, or if it is of a category of no interest to the ship's master. If it is a new and wanted message, it is printed on a roll of adding-machine size paper; if not, the message is ignored.

INMARSATSatellite systems operated by the Inmarsat, under contract to the International Maritime Satellite Organization (IMSO), are also important elements of the GMDSS. Four types of Inmarsat ship earth station terminals are recognized by the GMDSS: the Inmarsat A, B, C and F77. The Inmarsat B and F77, an updated version of the A, provide ship/shore, ship/ship and shore/ship telephone, telex and high-speed data services, including a distress priority telephone and telex service to and from rescue coordination centers.

The F77 is meant to be be used with the Inmarsat C, since it's data capability does not meet GMDSS requirements. The Inmarsat C provides ship/shore, shore/ship and ship/ship store-and-forward data and email messaging, the capability for sending preformatted distress messages to a rescue coordination center, and the Inmarsat C Safety NET service. The Inmarsat C Safety NET service is a satellite-based worldwide maritime safety information broadcast service of high seas weather warnings, NAVAREA navigational warnings, radio navigation warnings, ice reports and warnings generated by the USCG-conducted International Ice Patrol, and other similar information not provided by NAVTEX. Safety NET works similarly to NAVTEX in areas outside NAVTEX coverage.

Inmarsat C equipment is relatively small and lightweight, and costs much less than an Inmarsat A, B or F77. Inmarsat A, B and F77 ship earth stations require relatively large gyro-stabilized antennas; the antenna size of the Inmarsat C is much smaller. Inmarsat also operates an EPIRB system, the Inmarsat E/E+, which is similar to that operated by COSPAS-SARSAT. In July 2002 IMSO notified IMO of the decision by Inmarsat to withdraw provision of Inmarsat A services as from 31 December 2007. On that date, Inmarsat A can no longer be used for any purpose.

Under a cooperative agreement with the National Oceanic and Atmospheric Administration (NOAA), combined meteorological observations and AMVER reports can now be sent to both the USCG AMVER Center, and NOAA, using an Inmarsat C ship earth station, at no charge. There is also no charge to register for this service and to receive the necessary Inmarsat C software.

SOLAS now requires that Inmarsat C equipment have an integral satellite navigation receiver, or be externally connected to a satellite navigation receiver. That connection will ensure accurate location information to be sent to a rescue coordination center if a distress alert is ever transmitted.

High Frequency

The GMDSS includes HF radiotelephone and radio telex (narrow-band direct printing) equipment, with calls initiated by digital selective calling. Worldwide broadcasts of maritime safety information are also made on HF narrow-band direct printing channels. To meet these GMDSS requirements, the Coast Guard has improved high frequency (HF) ship-shore radio safety services from the Communication Stations to the maritime community, as well as narrow-band direct printing broadcasts.

Search and Rescue Radar Transponders (SARTs).

The GMDSS installation on ships include one or more search and rescue radar transponders, devices which are used to locate survival craft or distressed vessels by creating a series of dots on a rescuing ship's 3 cm radar display. The detection range between these devices and ships, dependent upon the height of the ship's radar mast and the height of the SART, is normally about eight nautical miles. Note that a marine radar may not detect a SART even within this distance, if the radar settings are not optimized for SART detection.

Digital Selective Calling

The IMO also introduced Digital Selective Calling (DSC) on VHF, MF and HF maritime radios as part of the GMDSS system. DSC is primarily intended to initiate ship/ship, ship/shore, and shore/ship radiotelephone and MF/HF radio telex calls. DSC calls can also be made to individual ships or groups of ships. DSC distress alerts, which consist of a preformatted distress message, are used to initiate emergency communications with ships and rescue coordination centers.

DSC was intended to eliminate the need for persons on a ship's bridge or on shore to continuously guard radio receivers on voice radio channels, including VHF channel 16 (156.8 MHz) and 2182 kHz now used for distress, safety and calling. A listening watch aboard GMDSS-equipped ships on 2182 kHz ended on 1 February 1999. In May 2002, IMO decided to postpone cessation of a listening watch aboard ships. That watch keeping requirement had been scheduled to end on 1 February 2005.

IMO and ITU both require that the DSC-equipped VHF and MF/HF radios be externally connected to a satellite navigation receiver. That connection will ensure accurate location information is sent to a rescue coordination center if a distress alert is ever transmitted.

VHF digital selective calling also has other capabilities beyond those required for the GMDSS. The Coast Guard uses this system to track vessels in Prince William Sound, Alaska, Vessel Traffic Service. IMO and the USCG also plan to require ships carry a Universal Ship borne Automatic Identification System (AIS), which will be DSC-compatible. Countries having a GMDSS A1 Area should be able to identify and track AIS-equipped vessels in its waters without any additional radio equipment.

ShipPlotter

From December 2004, all ships over 300 tons must carry an AIS system which broadcasts information about the ship to any suitably equipped receiver. AIS uses very short bursts of high speed data on two VHF channels in the marine band. The two frequencies used are 161.975 (Marine ch 87) and 162.025 (ch 88) MHz. Ships broadcast their identity, position, course, speed and destination so that other ships can take account of their movements. Using a low cost radio scanner tuned to one or other of these channels and ShipPlotter software running on your PC, you will be able to see a radar-like real-time map of all the large ships maneuvering in your area together with information about their destination, estimated time of arrival and even the dimensions of each vessel. ShipPlotter decodes the AIS digital signals from each ship using the sound card in your PC. You need a suitable VHF band radio receiver tuned to one of the two AIS channels. The program decodes the received digital data and displays it in a variety of formats.

A DSC-equipped radio cannot be interrogated and tracked unless that option was included by the manufacturer, and unless the user configures it to allow tracking. U.S. shore-based radio stations currently exist to support every element of the GMDSS, except for digital selective calling. The United States intends to declare an Sea Area A1 in 2006 and a Sea Area A2 (for the contiguous US) on 1 October 2002.

Use of GMDSS for Routine Telecommunications

GMDSS telecommunications equipment should not be reserved for emergency use only. The International Maritime Organization in COMSAR Circ.17 encourages mariners to use that equipment for routine as well as safety telecommunications.

SOLAS Ships

Ships subject to the Chapter IV of the Safety of Life at Sea (SOLAS) Convention have to fit GMDSS equipment. These include all ships engaged on international voyages except:
-Cargo ships less than 300 gross tonnage,
-Ships of war and troopships,
-Ships not propelled by mechanical means,
-Wooden ships of primitive build,
-Pleasure yachts not engaged in trade,
-Fishing vessels, and
-Ships being navigated within the Great Lakes of North America.

GMDSS for Recreational Boaters

The Global Maritime Distress and Safety System (GMDSS) is an international system using advanced communications technology. Development of GMDSS was initiated by the International Maritime Organization (IMO) and the system represents a significant improvement in maritime communications. GMDSS is designed to enhance ship-to-shore communications and provide rapid, automated distress alerting, with positional information if available. While compliance is mandatory for large cargo and passenger ships on international voyages or in the open sea, it is voluntary for recreational vessels.

GMDSS will however have an impact on recreational boaters, and it is recommended that recreational boaters become familiar with its features. To help with the transition to GMDSS, Coast Guard stations will continue to monitor VHF channel 16 and MF frequency 2182 kHz for the foreseeable future. The mandatory equipped vessels however, discontinued monitoring MF frequency 2182kHz on February 1st, 1999, and are only obligated to monitor VHF channel 16 until February 1st, 2005. The GMDSS equipment on these vessels will instead be monitoring for digital data on VHF channel 70 and MF frequency 2187.5 kHz.

This may present problems for non-GMDSS equipped recreational vessels attempting voice communications with mandatory GMDSS equipped vessels.

The mandatory equipped vessels have increasingly stringent equipment carriage requirements as they transit from Sea Areas A1 through A4. Most recreational vessels operating in Sea Areas A1 and A2, who wish to participate on a voluntary basis, will equip with a Digital Selective Calling (DSC) capable radio suitable to it’s normal operating area, and/or a 406 MHz Emergency Position Indicating Radio Beacon (EPIRB).

Ideally, navigational positioning equipment such as GPS or Loran is also highly desirable. When interfaced with the DSC radio, GPS or Loran provides vessel position information automatically, an obvious valuable safety feature.

THE DSC RADIO

The Digital Selective Calling (DSC) radio is a component of GMDSS that may be used by recreational boaters. As of June 17, 1999, all new models of marine radios (other than hand-held) produced for sale in the U.S. were required tohave DSC capability. Radio manufacturers may however, continue to produce non-DSC capable radios approved prior to this date.DSC radios are readily identifiable by the distinctive, dedicated red button marked “DISTRESS”, many with a protective lid or cover.

So while voice communications on the traditional channels/frequencies will continue, DSC radios provide a number of very important and desirable additional features. All DSC radios can automatically send a DISTRESS alert and message to coast stations and other DSC equipped vessels in the immediate area, at the press of a button! To further enhance safety, interfacing a GPS or Loran with the DSC radio is highly recommended. The automated Distress message usually provides information as to the identity of the vessel, nature of the distress, location of the vessel, and sounds an alarm at other DSC equipped stations. Ship stations should not acknowledge a DSC Distress Alert via DSC unless requested to do so by a Coast Station or an RCC (Rescue Co-ordination Center).

The acknowledgement is normally expected to be made by the Coast Station. Boaters should attempt contact on channel 16, relay the distress if necessary, and make sure the shore station is made aware of the distress. Follow-up voice communications on VHF channel 16 are carried out as in the past. DSC capabilities are not limited to emergencies. “ALL SHIPS” Urgency and Safety Alerts may also be received and sent to or from coast stations and all DSC equipped vessels in the immediate area. The actual Urgency and Safety messages are carried out by normal voice communications on the channels/frequenciesindicated in the DSC Alert.

IMPORTANT - DSC equipped vessels and shore stations, are assigned a unique identity number, known as a Maritime Mobile Service Identity (MMSI) number. The MMSI consists of nine digits, the first three identifying the country of origin - for example the continental United States numbers are either 303, 338, 366, 367, 368 or 369, while Canadian vessels are assigned 316. “Fleet” vessels have one 0, and Coast Stations have two 0’s preceding the country identifier.

It is essential that all vessels with DSC radios obtain an MMSI number, and have it programmed into the radio. Recreational boaters that purchase DSC radios are required to do this before using the DSC functions of these radios. MMSI numbers are currently available from Boat U.S. (BoatUS.com), West Marine, and other boating organizations for U.S. recreational boaters at no cost. In Canada boaters may obtain their MMSI from Industry Canada at no cost.

Routine contacts may also be made between individual DSC equipped vessels. By entering the unique MMSI number, a digital message is sent, sounding an alert on the vessel being called. A message is displayed advising the vessel of the specific channel/ frequency on which voice communications are to be carried out. Upon acknowledgement (digitally), both vessels change to the specified channel/frequency for voice communications. With appropriate DSC equipment there is then no longer a need to establish routine contact with another vessel on the usually very busy calling/distress voice channel such as VHF channel 16, or MF frequency 2182kHz. Such DSC equipped vessels will contribute significantly in reducing the present congestion on these channels.

Summarizing, the DSC radio enables vessels to rapidly transmit a DISTRESS alert and message, digitally alert other vessels that an URGENCY or SAFETY message is about to be sent, and establish contact with other vessels and coast stationsdirectly without having to use the voice calling/distress channels. The DSC radio automatically, and silently, maintains a listening watch on the appropriate DSC channel or frequency (VHF Ch70 or 2187.5 kHz).

It should be noted that the U.S. Coast Guard infrastructure to respond to DSC calls - including distress alerts - will not be fully completed until at least 2006. Boaters that choose to equip with DSC radios should therefore continue to use channel 16 or 2182 kHz for distress alerting purposes until the appropriate Sea Areas are declared operational.

EDUCATION

Recreational boaters are encouraged to learn more about GMDSS before installing this equipment on their vessels. A major concern is the high number of “false alerts” already being experienced with this system. A large percentage isattributable to inadequate familiarity with the equipment, and lack of operator proficiency.

GMDSS is a relatively new system and as such, all mariners - including recreational boaters, - should obtain some training in the proper use of this equipment. Boater education organizations such as Power Squadrons, Coast Guard Auxiliary, and others can assist with the required training.

Top of International Maritime Regulations page