Global Maritime Distress and Safety System
1. Introduction
The GMDSS is a complex but effective communications system. For the first time, a ship in distress does not have to rely on any other ship being within VHF radio range to have its distress message passed on; this is because the system uses satellite and automated terrestrial systems to ensure that a distress message is transmitted to a rescue co-ordination centre (RCC) and other ships for any given area of sea, automatically and at the same time. This is a huge advantage because it not only reduces the time it takes for a distress message to be received and acted upon (alerting the rescue services and allowing the RCC to home in on the source of the distress message quickly), but it also removes a potential point of failure in that, for example, if no ship hears the distress message, there is no possibility of it being acted upon. All passenger ships regardless of size and all cargo ships of 300 gross tonnage and upwards are required to fit GMDSS equipment. The obligations of Contracting Governments to provide shore-based facilities using satellite technology mean that a distress alert can, in theory, be initiated anywhere on the world’s oceans or seas and the ship’s position can be communicated to those who need to know, wherever they are. Also, vessels which sail on the same waters as us are now more likely to hear our distress message and be in a position to respond. This was not the case when distress messages were sent by simple VHF radio or MF long range radio – transmission range was normally limited to about 30 miles for VHF and 40 miles for MF and so any one ship was relatively unlikely to be close enough to be able to assist. Modern GMDSS equipment is capable of receiving messages from other ships which transmit a particular type of position update message; in the case of the equipment I will cover in a later article, receiving these messages is an automatic function of the equipment and is done every 15 minutes so long as the equipment is turned on and receiving what is known as the digital selective calling – but more of that later. And the equipment can also be used to send a distress message, along with the ship’s current position and time of the distress, in a similar automatic fashion.
1.1 Background
Nowadays, the GMDSS has become an important system in maritime communication for distress and safety purposes. It is not only about the established technology, but it will also be the future. The latest technological developments in the field of satellite technology for mobile communication will contribute to the improvement of the GMDSS, as we can infer from the ongoing work on the next generation of the GMDSS. Such future developments are also addressed in the last part of this article.
Since that time, the GMDSS gradually replaced the ship-to-ship safety system, the NAVTEX, and the HF NBDP with DSC distress and safety system. It has also introduced an entirely new, integrated communication system by using modern technology like satellite and digital.
In 1988, the work on the GMDSS concept was completed at an IMO Diplomatic Conference in London, followed by the adoption of amendments to SOLAS, which made the GMDSS components and provisions mandatory on 1st February 1992, by Resolution 10 of the same conference.
The use of satellite-based communication for safety purposes, including SAR operations, was outlined for the first time in Resolution 106(30) of the International Maritime Organization (IMO) in 1977. This was followed by Resolution 39(8) in the same year, by which the IMO stressed the need to establish a new, global maritime distress and safety system to take advantage of the new technological possibilities.
1.2 Significance of the Global Maritime Distress and Safety System (GMDSS)
The GMDSS, as it is known today, was developed in the 1970s as a result of the increasing need in the maritime community for a more effective and reliable means of initiating and controlling emergency communications and quickly locating the source of distress. Before the development of the system, various maritime safety organizations such as the International Maritime Organization (IMO) and the International Telecommunication Union (ITU) were utilizing coast stations and satellites for tracking and locating ship-to-shore and shore-to-ship communications, but these older systems were not integrated or automated, and ships at sea were not able to direct a distress alert to specific rescue authorities. Coastal agencies then had to rely on former manual radio systems and landline telephones to track the alerts and pass rescue information between different national authorities, which made coordinated international maritime distress response efforts much slower and difficult. Coast stations with extended range and satellite systems are used to provide the means of receiving ship alert information and communicating it to the appropriate shore-based authorities around the world. The coast stations and the satellites are in turn linked by the means of the land earth stations. Nevertheless, the real significance of the GMDSS is that the vessels themselves are now able to automatically and without human intervention transmit ship-to-shore distress alerts. This capability is called the “automatic” mode. The second feature of GMDSS is that distress alerts will not only be received by the nearest coast station but through the use of digital techniques, the identity and location of the vessel in distress and the fact that a distress message has been received is automatically printed out at any other coast radio station which might also receive the alert, as well as on all other ships which are equipped to receive distress alerts. This feature allows for the much quicker and more efficient use of this information to provide assistance to the vessel in distress. Furthermore, a shore-to-ship safety alerting service for sending meteorological warnings or search and rescue information and also a general radio-telephony calling service for establishing contact between ships is also available under the GMDSS. The significance of the GMDSS for safety is that this integrated system provides the most extensive and advanced means of locating and assisting vessels at sea in distress of any other system yet developed. It is intended to perform that vital function which epitomizes the special character of satellite-based ship systems, namely global real-time interactive communications and information transfer between the ship and competent shore authorities. It is hoped that a better awareness and clearer understanding of the potential offered by GMDSS in the areas of distress and safety may be achieved in the maritime community through the continued education and training of the maritime and shore-based personnel who are charged with the operation and functioning of this new system.
1.3 Objectives of the Dissertation
Therefore, the main objectives of this dissertation have been decided as – to provide a complete picture of GMDSS, its historical development, and the legal framework required for the implementation of GMDSS; to explain the communication procedures and the main aim of the GMDSS to enable efficient and effective search and rescue operations. Further, to analyze the developments in satellite communication and information technology which lead to the technological shift from the existing analog base system to the digital satellite-based network; to evaluate the effectiveness of GMDSS in terms of coastal states and vessels’ obligations on providing SAR services. Also, to evaluate the effectiveness of the SAR services in the UK and give an idea as to whether the UK complies with its obligations under international maritime laws concerning the provision of SAR services. And finally, to analyze the potential challenges and limitations of GMDSS. The main objective of GMDSS is to establish an international system for distress, safety, and routine communication in the maritime field by utilizing modern satellite and digital technologies as well as the existing terrestrial and radio communication systems. The system is designed in such a way that it ensures the rapid and reliable transmission of the distress alert from the ship to the rescue authorities irrespective of the position of the ship in the sea. Also, the system should be capable of providing ship-to-ship distress alert. The GMDSS also provides the means for the rescue coordination and on-scene search and rescue authorities to eliminate the ship’s position error, and it also provides for public correspondence for the search and rescue services. The automated digital selective calling function is also employed in the GMDSS. By pressing two or three buttons, a ship station can send a distress alert to the coast earth station which will in turn send a message to all ships in the local areas. The distress alert shall include the ship station’s identification, the position of the ship, and the nature of the distress. Moreover, in response to the distress alert, the receiving ship’s earth station will automatically call the distress ship. After the establishing of the satellite link, the distress message will be sent, and the people in charge at the shore side can also get the message from the shore-based earth station. And the GMDSS is now using such a sophisticated system called maritime safety information broadcasting. Infrared and low power digital selective calling devices may be used for alerting and locating a person overboard at night or in poor visibility. The system has to be provided in the area covered by the International Maritime Satellite Organizations.
2. Overview of the Global Maritime Distress and Safety System
To achieve the provision of maritime distress and safety communications which are effective and promote the protection of life, the international community, through the International Maritime Organization (IMO), introduced the Global Maritime Distress and Safety System. The GMDSS is intended to perform the following functions as stated in the IMO resolution A.703(17): to automate and make as far as possible, distress and safety communications; to increase the probability of a ship, shore station or rescue coordination center (RCC) receiving the distress alert; to reduce the time required for locating the potential search and rescue (SAR) target; to provide for the rapid and automatic transmission of signals and calls which are readily accessible to the master of the ship; and to ensure maximum availability of the radio communication systems. The functioning of the GMDSS is based on the signification of various distress messages that are to be transmitted in accordance with the procedures as in chapter IV, which makes explicit provision for the introduction of digital technologies. The most significant element of the system is the concept that radio communications should rely on a number of search and rescue locating techniques and encode one of the seven kinds of digital selective calling. The future development of the GMDSS and other maritime safety technologies must be seen within the context of maritime safety overall. The continuing process of technological advancements, particularly in the area of digital technology, offers scope for the introduction of further measures to improve the search and rescue environment and to enhance the protection of lives at sea. As member states of the European Union look forward to the full implementation of the automatic identification systems.
2.1 History and Development
Also, a GMDSS concept north Asia regional test bed was approved, and maritime industry stakeholders there are excited to explore the benefits and applications of e-Navigation and viable ways of modernizing GMDSS, besides enhancing the national maritime infrastructure. GMDSS has indeed saved countless lives since its implementation and has significantly improved the level of safety within the maritime community. However, as vessels and user requirements continue to evolve, the system has to adapt in order to remain effective. Such evolution is exemplified through the various plans and constantly progressing infrastructure developments in the next generation of maritime distress and safety communications.
With ongoing technological advances, the GMDSS has to evolve to take advantage of the latest technology offerings and to ensure the provision of the most effective and efficient distress and safety communication in the future. The latest ongoing development is the introduction of the system, which is called “GMDSS modernization and e-Navigation”. This focuses on the e-Navigation test beds, which are based on the concept of the marine ‘Situational Awareness’ through the use of a variety of data sources, to replace paper nautical charts for improved safety. Also, it proposes the integration of maritime telecommunication systems with GMDSS to form an e-Navigation infrastructure for improved communication and information management, and this will benefit from the seamless and integrated process and automatic transfer of shipping data.
The maritime safety information on NAVTEX has also to be incorporated in the GMDSS to be operationally and SOLAS mandatory, starting from 1 August 1993. NAVTEX is a broadcast system, which is based on the reception from ships of navigational and meteorological warnings and other urgent information that are automatically printed on board the ships. Delegates to IMO have approved the planned introduction of the new long-range satellite navigational and meteorological warning broadcast system, namely the new IOR system, to provide wider coverage and greater functionality for the masters and the seafarers.
At the heart of the GMDSS is a new concept of satellite-based search and rescue system, which has the function of locating and alerting the rescue services to a ship in distress. This system is known as COSPASSARSAT. It uses a number of satellites, each of which is capable of detecting a distress alert signal from a ship or from a survival craft. The alert signal is characterized by a particularly fast and accurate fixing of the position of the distress. The COSPASSARSAT system is currently in use, but it is expected that the MEOSAR system will replace this in due course. The MEOSAR (Medium Earth Orbit Search and Rescue) system also uses the COSPASSARSAT payloads on the low orbit satellites while adding the detection capabilities of the next generation of search and rescue satellites on the medium orbit. This system modernizes and improves the existing search and rescue capabilities and provides greater accuracy in locating distress.
The GMDSS represents a significant step in the improvement of maritime safety and development. The system became necessary as the maritime mobile frequency bands were becoming more crowded, satellites were making a greater contribution to maritime communication and after the introduction of digital technology, such as satellite communication and direct printing. Therefore, a number of amendments to the SOLAS Convention were made to implement the GMDSS and the associated radio installations, and these changes came into force on 1 February 1992. A full GMDSS installation often includes satellite systems, such as INMARSAT and the new COSPAS-SARSAT system, as well as the existing MF and HF systems.
2.2 Components of the GMDSS
These components and other elements allow the GMDSS to be effective. When a distress signal is made, the GMDSS will make use of the most appropriate means of communication. This could be anything from using one satellite to many satellites, depending on location. It is important to realise that not all ships will have the same systems; older vessels may not be able to handle digital transmissions so may be using telex or even the very high frequency (VHF) system. New ships are being encouraged to install the latest terminal and telex systems as opposed to the older systems. All in all, the GMDSS is made up of several different integrated components that are responsible for achieving effective distress and safety communications. With the implementation of the system, the main focus is on connecting the individual elements in such a way that the likelihood of failure is minimised, and the security and surrounding environment is maximised. The future of the system promotes advancements in technology through the development of new technologies and the exploitation of satellite communications. A future GMDSS could see the use of not only the current satellite systems but also the integration of current and future terrestrial communications systems. This will lead the way for ‘dual mode’ or ‘multi mode’ communications, effectively boosting the performance of the GMDSS even further. Also, research is being conducted by the international community looking towards the use of digital communications to improve the GMDSS. It is expected that any such research would be directed at both the improvement of the system’s capabilities and the reduction of systemic costs. The effectiveness of establishing dedicated digital satellite channels for GMDSS communications is being researched to allow the timely and automatic transfer of distress alerts to the relevant maritime rescue coordination centre. Developments in ship earth stations are being monitored and encouraged so that ship earth stations can quickly become smaller and more effective in providing shipborne communications. A ship earth station (SES) is a ground earth station located in any mobile maritime satellite service station. Traditionally, a SES for the Inmarsat system would be a large and static unit, however advancements will soon lead to the availability of smaller and more flexible units for maritime use. It is anticipated that such developments in SES technology will allow even smaller vessels, like leisure craft, to benefit from the safety aspects of GMDSS. All in all, from the initial conception of the GMDSS do my homework market to future enhancements and developments, the main purpose of the system is to make the best use of the new and emerging technologies to reduce the likelihood of failures in the transmission of distress alerts and information. The GMDSS has been praised for providing an increase in maritime safety and for providing a more effective use of resources by providing for the integration of new and existing communications resources.
2.2.1 Shipborne Equipment
2.2.2 Shore-based Infrastructure
2.2.3 Satellite Systems
2.3 International Regulations and Standards
The International Maritime Organisation (IMO), which is a special agency of the United Nations, has provided the comprehensive framework for the maritime safety which includes not only the establishment of the GMDSS but also its implementation. The International Telecommunication Union (ITU) is an alternative international organisation which has a crucial role in ensuring the effectiveness and functioning of the GMDSS. The ITU must maintain the international regulations in relation to the radio communication as well as the radio frequency spectrum utilisation to guarantee that the GMDSS would be functioning in an effective manner. The ITU has established the international standards for the satellite systems and conventional satellite EPIRBS (Emergency Position Indicating Radio Beacon). As the GMDSS system provides various satellite services including the Inmarsat, Cospas-Sarsat and the new high frequency digital satellite system, the coordination among the member states and international organisations is considered to be really important in order to operate those satellite systems efficiently. Every ship is required to complete a radio safety survey which is a comprehensive inspection of the whole radio communications equipment on the ship. The survey is required before the initial issuing of the safety radio certificate by the flag state and it should be carried out under the regulation of the International Convention for the Safety of Life at Sea which is known as SOLAS. The safety radio certificate would be issued by the flag state after the ship is found to comply with the relevant requirements. It is really important to note that the survey should be carried out by the properly qualified and experienced radio inspector. The survey could help to make sure that all the radio equipment is in good condition and it is capable of working with the GMDSS in the event of an emergency. Moreover, it could help the inspection of the recognised organisations and the flag states’ surveyors to cross-check the compliance of the GMDSS on certain ships which is crucial to guarantee the maritime safety. Speaking of the onshore requirements, there are a number of primary and secondary GMDSS public coast radio stations located all over the world. These stations are managed and maintained by the respective government and they must maintain a continuous radio watch over distress and safety frequencies in order to coordinate and assist the distressed ships. The primary GMDSS coast radio station is equipped with the satellite services and each of the primary station will have its own search and rescue area of coverage. It is a mandatory requirement for ships to be fitted with the two console type Inmarsat C as well as the separate printer unless the flag state has granted a valid exemption. This requirement is in accordance with the SOLAS regulation IV and it aims to make sure that any distress alert could be automatically printed out near the master’s or navigation officer’s console and therefore, a more efficient and quicker response could be expected. More critically, this requirement enables the master or the navigation officer to be aware of the ongoing distress alert and they could respond in a timely manner to the distress situation. As a result, the safety and more importantly, the protection of the life at sea could be enhanced. Moreover, it could help the coast authorities to quickly identify the source of the distress signal so that a more effective and efficient search and rescue operation could be carried out which is crucial to save more life at sea.
3. Functioning and Implementation of the Global Maritime Distress and Safety System
When a distress alert is sent out by a ship through the system, it would include the ship’s identity, the type of emergency, and the date and time of this position. If the ship’s position cannot be given automatically in the distress alert, the system should have the ability to manually input the ship’s position as well. Once a distress alert has been triggered, the ship Earth Station (the Coast Earth Station) will inform the appropriate search and rescue authorities immediately (ITU, 2019). The coast Earth station would then send the distress alert repeatedly to ensure that the receipt of this distress alert is acknowledged to either the Coast Earth Station or the ship. In many cases, the Coast Earth Station would be unable to defeat the distress alert, and then it is up to the search and rescue authorities to inform the coast where the distress is heard. Rescue coordination would be best managed if the distress information and the respond information between different parties are passed automatically. GMDSS would initiate the process of marking the continuous position of all the ships, so that when a distress alert is received, the position it indicates would be the last position of the relevant ship, in the case that the position in the distress alert has not been updated. It is the most valuable when the ships automatic owe shipborne equipment and the Earth station system are relied upon. On the other hand, if the system is considered to fail, the master of the ship or the responsible navigator should not delay in operating alternative medium or methods to gain the manual distress communications. On the other hand, if the system is considered to fail, the master of the ship or the responsible navigator should not delay in operating alternative medium or methods to gain the manual distress communications. In terms of the satellite system failure, it shall not affect the performance of other systems as the satellite system is used as a method of establishing distress alerts, and it is not used for the transmission of Maritime Safety Information (Boyce, 2011). If the DSC fails, the GMDSS provisions allow for radio equipment utilizing other non-automatic means to meet the functional requirements for the operation of radio installations for distress and safety communications. The system performance in practice of the GMDSS is reliant upon the quality of the communication systems, and it is critical to ensure that the satellites and the Earth stations can provide a continuous alerting and locating potential. However, it is not to say that the system defines improved and more accurate locating technology. A development of GMDSS is in progress, led by the International Maritime Organization (COMSAR, 2019), and it requires ships to enhance the shipborne communication systems in their new building. GMDSS shall be maintained, which means existing ships would have to total comply with GMDSS as well, but in relation to the future of GMDSS, digital marine technology is promising. The Iridium GMDSS (Iridium, 2019) has just received recognition from the IMO, and it pushes the boundaries of ship safety and distress communication which can further improve the performance of distress alerting and locating. GMDSS is based on the concept of communicating with the combination of satellite and Earth-based communication services. The definition of satellite and Earth station system is to provide global coverage in the system in ensuring the provision of distress alerting and other communication services.
3.1 Distress Communications
During a distress situation, the ship earth station is to be activated automatically to establish a connection with a coast earth station through either the Inmarsat geostationary satellites or the long-range maritime VHF radiotelephone systems. The ship earth station can also be manually switched on in order to establish a distress alert connection through other satellite systems. It is necessary for the distress alert to contain, among others, the identification of the ship, the ship’s position, and details of the distress suffered by the ship; and then the distress alert is to be transmitted to the coast earth station. For satellite systems, the distress alert connection will thus be established between the ship and the relevant earth station before the distress alert can be transmitted; and the position should be included in the distress alert. On the other hand, the long-range maritime VHF radiotelephone systems enable the distress alert to be transmitted directly from the ship to any coast stations within the transmission range. The shore-to-shore working and group calls are to be established through scanning the Ch.70 and monitoring Ch.16 in the Digital Selective Calling mode. The procedures require that all ships using the DSC have to maintain a continuous DSC watch on Ch.70 when the ships are in any state of sea-going. When a distress alert is received on any coast stations from a DSC watch receiver, the alert is considered as being received simultaneously on Ch.70 frequency. At the same time, the coast station is free to allocate a voice frequency to talk to the distress ship. As for the group calls, the coast stations should normally acknowledge the receipt of the alert to the sending ship. However, a coast station has the ability to decline acceptance of the distress information if it has no time to manage the distress traffic. In that case, the shore-to-shore working and group call will cease immediately. By doing so, the distress traffic in the Digital Selective Calling systems can be effectively managed, and unnecessary or false distress alerts will not be transmitted over the voice communications.
3.1.1 Distress Alerting
3.1.2 Distress Relay
3.1.3 Distress Coordination
3.2 Safety Communications
Another key feature of the GMDSS is that it provides an integrated communications structure for promulgating maritime safety information from many sources. The system is designed to perform safety-related communications during the period in which a ship is in distress and proceedings for the safety of persons and property are taking place. These communications also have priority. It is important to note that any communication concerning the actual distress situation and its coordination must have absolute priority over all other traffic. Standard procedures in the GMDSS require each ship’s radio officer to continuously and closely monitor all the distress and safety frequencies to ensure that the communication and coordination at the shipping level can be made as quick and effective as possible. The ship earth station and coast earth station are programmed to send the automatic distress alerts; however, it is expected that the communications officer should also be ready to transmit the distress alert message manually if necessary. As such, the GMDSS requires not only to transmit the urgent message to the search and rescue team once the distress conditions are identified, but also to maintain an effective communication among various parties that might involve in the rescue procedures; because each message exchanged among the parties will be observed by the other ships that stand by if necessary. Therefore the rescue coordination and procedure may be more efficient, when providing that the communications officers of the ships in the vicinity know well about how to handle and coordinate the transmission of the distress messages. Up to this point, the understanding of the GMDSS set forth has been described from a very practical point of view; however, it should be noted that both the SOLAS and relevant national legislations changes or updates from time to time and thus require the attentive communications officers and masters of the ships as the users of the GMDSS to remain familiar with the latest required standard of the system.
3.2.1 Ship-to-Ship Communications
3.2.2 Ship-to-Shore Communications
3.2.3 Search and Rescue Operations
4. Evaluation and Future Perspectives of the Global Maritime Distress and Safety System
In order to evaluate a system like the GMDSS, its performance needs to be measured. For this purpose, many nations and organizations use measures like availability of the system, probability of failed communication, transmission and response time. The research conducted by Soliman and Hekal (2016) indicates that the GMDSS has been proved a good and effective system for sending and receiving distress alerts and similar communications. The system ensures that a ship in distress can quickly make initial contact with the coast guard or a rescue coordination centre, even if the crew has, for example, to abandon ship and take to the lifeboats. Similarly, different types of safety communications can be implemented in the GMDSS. For instance, the digital selective calling (DSC) technology is explained by Hatfield and Canessa (2005) as a method for establishing contact between ships and between ships and coast stations. This process is mainly operated inside the GMDSS and it is used for sending and receiving distress alerts and other types of digital messages as well as for establishing routine communications too. However, it is constantly being faced with the challenge of meeting future demands, from both a technological and a clinical perspective. One critique towards the GMDSS is due to the presence of a number of different systems which need to be connected together to achieve an agreed information exchange. Whiler also indicates that, the continuing expansion of the use of satellite technology introduces possible alternative solutions to the problem of alerting ashore in the event of a maritime mobile distress. The widespread and growing use of very small aperture satellite systems that employ code division multiple access technology could allow the development of tailored satellite systems for use only in distress alerting as the technology matures. Such systems, says Whiler, may well bring about an improvement in the overall reliability and the availability of alerting fixed earth stations. Meanwhile, Volkhard (2010)’s research refers to the investigation of the application of modern communication technologies on the GMDSS. He mentions the research project EuroGMDSS, which is aimed at the development and verification of functional and operational concepts for the evolution of the European GMDSS from an equipment orientated to a VDES based, integrated communication and navigation system, in compliance with international regulations and taking advantage of the said technology. This could potentially lead to the proposal to modify the GMDSS to incorporate the use of additional modern satellite-based communication systems, such as the VHF data exchange system (VDES) over satellite; and to allow the GMDSS to benefit from the use of the global maritime distress and safety system (GMDSS) carrying regime-compliant and type-approved maritime mobile service identity (MMSI) numbers.
4.1 Effectiveness and Efficiency of the GMDSS
The effectiveness and efficiency of the GMDSS are evaluated based on the performance of the system in handling distress and safety communications. The devolution of the GMDSS from the traditional maritime safety system using high frequency radiotelephone to the present satellite-based digital system has drastically improved the maritime distress and safety system. As of now, approximately 80% of the world’s oceans and seas are under the coverage of the satellite system. The system has very good reliability mainly due to the automatic detection and relay of distress alert in the form of digital signal which eliminates human errors. It is a very secure system in the safety of life at sea, and further enhances the safety communication and operation of the rescue coordination. Every year a substantial number of vessels and lives are saved through the effective usage of the system. For the efficiency, the GMDSS provides various means for communication of which the most suitable one may be used for a particular situation. With the proper usage of the communications and urgency of the distress being sent, unnecessary congestion of traffic in the medium frequency and high frequency could be avoided. Besides, recurrent training courses on the GMDSS and radio communications are provided to the maritime community. These training courses are essential especially to the seafarers in the understanding of the operation and applications of the latest satellite communication system. As such, they will be able to adapt and use the system correctly in case of emergency. The effectiveness and efficiency of the system have best demonstrated and upheld by the successful rescue of a sailor, Tony Bullimore, in the Southern Ocean on 9th January 1997. When his yacht capsized, a distress message was sent using the GMDSS and within a few minutes the rescue mission was coordinated with the help of the system and he was saved. On the contrary, the traditional maritime safety system using the high frequency radiotelephone was not efficient as the manual distress calls may be subjected to various kind of impediments such as human errors, language difficulties and at times ignorance of the distress messages by the operator. The GMDSS has definitely enhanced the capability of the rescue or search teams in areas where it is not covered by the conventional radar systems which are in operation today. However, the digital selective calling technology, which is the fundamental of the GMDSS, is still evolving in the field of maritime communication. The conversion from the present high frequency radiotelephone system to the satellite-based distress and safety system is expected to be completed in the near future. As the technology improves, global coverage of distress alert, which is the present Inmarsat system, may be further widened especially in the polar region, and thereby provides better solutions to the distress alert and co-ordinate the searches over a wider area. Every day there are new ideas and improvements being created. It is also believed that the GMDSS will forge ahead to continue saving even more lives and better property at sea in future. Every single effort by the International Maritime Organization, the manufacturers and the rescue coordination centers of the GMDSS will surely be translated into great success and embraces the objectives of the Global Maritime Distress and Safety System.
4.2 Challenges and Limitations
The challenge and limitations faced by the system are numerous. Because of the integration of the satellites as a communication tool, over-reliance on this technology often leads to system failure, especially if the satellite may develop a technical fault. From the history and the development of satellite communication, because it was only in the late 20th century, the number of satellites in the orbit has increased – this has improved satellite communication. However, the reduction in the cost of satellite use has allowed the allocation in the low Earth orbit, which has made the maintenance of a satellite system very difficult. Besides that, due to the bandwidth limitations and the management in satellite communication, every user of the satellite system has to use the bandwidth efficiently in order to allow other users to communicate by the same satellite. With that, in order to use the bandwidth efficiently, the users have to form into the network, which is usually termed as the ‘CLS’ – Communications Land Earth Stations. However, many isolated Earth stations still have a direct connection to the satellite, and this leads to congestion – the maximum available bandwidth from the satellite would never be obtained if the users do not structure into a CLS network, causing inefficiency in GMDSS communication. Not only that, the proper communication and the problems occurred from this ‘progress’ of satellite communication made the authority start guidelines and rules, which led to the development of the ‘GMDSS’. The satellite communication has to move from the slow and inefficient ‘Circuit Switch’ technology to the much more effective ‘Packet Switch’ technology, in which there is a development of the satellite in the high Earth orbit, which covers the whole globe and a much better terrestrial communication. As a result of the development and the advancement of satellite technology, nowadays, there is a new project that should bring worldwide coverage satellite communication to the GMDSS – it is the project ‘Iridium’. This satellite project should make the integrity and availability of GMDSS communication much better. When the project finishes and the Iridium technology becomes fully operational, there is a plan to supplement the existing satellites for GMDSS with the Iridium type satellite. However, to switch into the Iridium satellite and therefore increase the GMDSS reliability, all the Coast Earth stations and the ship’s satellite system have to make an enormous change in their system and their technology – which costs a lot. All these factors lead to the challenges faced by the system and significant debate in the maritime industry about the proper implementation of the GMDSS.
4.3 Technological Advancements and Potential Enhancements
One of the main advantages of the GMDSS as an international safety system is that it uses the latest technology to make it easier for mariners in distress to locate and communicate with the relevant rescue services. GMDSS uses satellite and advanced terrestrial communications to ensure distress alerts are transmitted rapidly – in a few seconds – to a Maritime Rescue Coordination Centre (MRCC) and in difficult circumstances, the initial alert will be automatically repeated. In the past, when a distress message was sent by Morse code, the strength and clarity of the signal was down to the skill of the radio operator who was sending it. Also, if the system was working near to its maximum operational range, it would not always be possible for the distress signal to reach the receiver. Nowadays, satellite communications are used to track and trace vessels in distress. When a distress beacon is activated, COSPAS-SARSAT (satellite-based search and rescue) takes less than a minute to pinpoint the position of the distress. Also, in the future, it is hoped that new technology will reduce the time taken to detect a location to ‘near instantaneous’. The GMDSS is an evolving system, which changes to take advantage of the latest technological developments. Many of the ‘new’ developments are in areas related to enhancing the effectiveness of search and rescue operations. Local authorities are considering how they can adapt and improve their communication networks and rescue infrastructures, and that search and rescue services are able to use them fully. For example, developments in mobile communication networks now mean that data, such as position information, can be sent along with a distress alert. This has led to the introduction of the Global Positioning System (GPS) into the GMDSS. This means that when a distress signal is sent, it can now include data about the vessel’s position. GPS is part of a new technology that is known as the ‘Long Range Identification and Tracking’ (LRIT) system. This is an international mandatory system, introduced by the International Maritime Organization (IMO) to improve maritime safety and to help in the protection of the marine environment. LRIT provides for the continuous global surveillance of vessels and sends position information at fixed regular intervals. This represents a leap forward for the safety of vessels and crews at sea and provides great opportunities to open up more technology initiatives that can continue to improve the GMDSS in the future. Also, global advances in technology mean that efficiency savings can be passed on to the public for the implementation of the system. For example, a new ‘intelligent network’ for the processing of digital messages; the ‘Maritime Safety Information’ (MSI) service depends on the broadcast or the update of information such as weather reports and navigation warnings. This technology is planned to be improved by the use of satellite communication for the broadcast of low-frequency messages. By the instrumentation of such new technology, it enhances the speed and frequency of data updates that are vital to modern navigation services. A satellite-based system has the potential to achieve a broadcasting rate of 10 MSI messages for every 5 minutes; this is a major efficiency technology adopted in the GMDSS over the traditional broadcasting by long-range transmitters. With proper utilization of these lightning-fast, fully automatic, digital methods, it will dispense with the requirement for manual message selection and individual initiation and actually means a selection of service providers can offer their MSI service globally to vessels, regardless of their geographic location. No doubt that it seems GMDSS is making the best use of the latest technological advancements to further improve the systems viable and widely available by setting up additional ground stations in the satellite network, ensuring coverage over even the most remote areas of the earth, and making further improvements in the efficiency of rescue operations that are demanded by this technological progress.
4.4 Future Directions for the GMDSS
When the GMDSS was first introduced in the 1990s, it represented a major leap forward in terms of maritime safety in comparison with the older systems which it replaced. However, the general philosophy behind the system has changed little in the subsequent period; its primary focus is very much the provision of safety-related communications of various forms, for example enabling distress alerts or indicating that a ship or other mariner is in some form of trouble, and providing the opportunity for the receipt of maritime safety information – for instance weather routing information, or details of a local notice to mariners. This remains the case even though the technology which is available to implement these general principles has moved on at quite a pace – for example, with the development of modern satellite-based systems which may offer certain advantages over the older, purely terrestrial radio services which were traditionally utilised to support the GMDSS. One suggestion from the NCSR, in response to this perceived mismatch between the static nature of the regulatory regime for the GMDSS on the one hand and what has been a period of sustained technological advancement on the other, has been to review the compulsory carriage requirements which set out the need for ships to carry certain types of GMDSS equipment. In particular, some have queried whether newer types of technology – for example, satellite distress communication systems and maritime safety information broadcasts via satellite links – might not add as much or more to maritime safety than the older, terrestrial-based infrastructure which continues to be the backbone of the system today. While any such change involving relaxing the requirements to carry older equipment is likely to be approached cautiously, given that the GMDSS has been very effective in supporting the saving of lives at sea, and a thorough analysis of the likely impact and costs to the shipping industry in any change would need to be carried out, there is an acknowledgement that it would be wrong to close the door to potential future safety enhancements for the world’s mariners as technology continues to develop.

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