GMDSS Handbook
  
 
Annex - 4-1
IMO/IHO World-Wide Navigational Warning Service Guidance Document WWNWS
 
INTRODUCTION
The original resolution of the tenth International Hydrographic Conference in 1972 recommended the formation of an ad hoc joint IMO/IHO Commission to study the "establishment of a co-ordinated, efficient global radio navigational warning service". Subsequently, this became a purely IHO Commission known as the Commission on Promulgation of Radio Navigational Warnings which nevertheless consulted continuously with IMO. In its report to the eleventh International Hydrographic Conference in 1977, the Commission submitted a Draft Plan for the Establishment of a World-Wide Navigational Warning System, also referred to as Plan for the Establishment of a Co-ordinated Radio Navigational Warning Service. The title World- wide navigational warning service or WWNWS used for this revised edition of the document reflects the evolution of the system from a proposed action to an effective co-ordinated service which now has all of its 16 NAVAREAs in operation. This revised edition contains changes necessitated by the advent of the global maritime distress and safety system (GMDSS), as adopted by the Conference of Contracting Governments to the International Convention for the Safety of Life at Sea, 1974, on the Global Maritime Distress and Safety System in November 1988, effective on 1 February 1992.
Future amendments to the guidance document will be considered formally and approved by IHO normally through the use of circular letters and by IMO through its Maritime Safety Committee in accordance with the procedures set out in annex 2 to this document. Proposed amendments will normally be evaluated by the IHO .Commission on Promulgation of Radio Navigational Warnings, which includes as an ex-officio member a representative of the IMO Secretariat, prior to any extensive IHO or IMO consideration.
 
World- Wide Navigational Warning Service (WWNWS)
1 INTRODUCTION
This document provides specific guidance for the promulgation of internationally co-ordinated NAVAREA and coastal warnings via HF Morse (A1A), NAVTEX and international SafetyNET services. It includes the situation where international SafetyNET is used in lieu of NAVTEX as the primary means of transmitting coastal warnings. Its guidance does not apply to purely national warnings services which supplement those internationally co-ordinated services.
2 DEFINITIONS
2.1. For the purposes of this service, the following definitions apply:
2.1.1. Navigational warning: A broadcast message containing urgent information relevant to safe navigation Types of information suitable for transmission as navigational warnings are described in 4.2.1.3.
2.1.2 Maritime safety information (MSI): Navigational and meteorological warnings, meteorological forecasts and other urgent safety-re1ated messages.
2.1.3 NAVAREA: A geographical sea area, as shown in the appendix, established for the purpose of co-ordinating the transmission of radio navigational warnings. Where appropriate, the term NAVAREA followed by an identifying roman numeral may be used as a short title. The delimitation of such areas is not related to and shall not prejudice the delimitation of any boundaries between States.
2.1.4 Subarea: A subdivision of a NAVAREA in which a number of countries have established a co-ordinated system for the promulgation of coastal warnings. The delimitation of such areas is not related to and shall not prejudice the delimitation of any boundaries between States.
2.1.5 Region: The part of a NAVAREA or subarea established for the purpose of co-ordinating the transmission of coastal warnings by NAVTEX or international SafetyNET broadcast.
2.1.6 NAVAREA co-ordinator: The authority charged with co-ordinating, collating and issuing long-range navigational warnings and NAVAREA warnings bulletins to cover the whole of the NAVAREA.
2.1.7 Subarea co-ordinator: The authority charged with the co-ordination of navigational warnings information within a designated subarea.
2.1.8 National co-ordinator: The national authority charged with collating and issuing coastal warnings in a region. 2.1.9 NAVAREA warning; A navigational warning issued by the NAVAREA co-ordinator for the NAVAREA.
2.1.10 NAVAREA warnings bulletin: A list of serial numbers of those NAVAREA warnings in force issued and broadcast by the NAVAREA co-ordinator during at leas the previous six weeks.
2.1.11 Coastal warning: A navigational warning promulgated by a national co-ordinator to cover a region. (Coastal warnings may also be broadcast by means other than those of the WWNWS as a national option.)
2.1.12 Local warning: A navigational warning which covers inshore waters, often within the limits of jurisdition of a harbour or port authority.
3 BROADCAST SYSTEMS
3.1 Broadcast systems
3.1.1 The radio systems to be used internationally for the promulgation of maritime safety information are laid down in the International Convention for the Safety of Life at Sea, 1974 (SOLAS), as amended. These include:
1. NAVTEX: Single frequency time-shared broadcast system with automated reception and message rejection/selection facilities. Use of NAVTEX is regulated by the IMO NAVTEX Manual (IMO publication 951);
2. international (enhanced group call) SafetyNET service: Dedicated satellite broadcast system with automated reception and message rejection/selection facilities. Use of this service is regulated by the International SafetyNET Manual;
3. HF Morse (A1A): Traditional manually operated radiotelegraphy system. To be superseded by the automated systems in .1 and .2 above on introduction of the GMDSS between 1992 and 1999.
3.2 Broadcast scheduling
3.2.1 Automated systems (SafetyNET/NAVTEX)
3.2.1.1 Navigational warnings should be transmitted as soon as possible or as dictated by the nature and timing of the event. Normally, the initial broadcast should be made as follows:
1. for SafetyNET, within 30 min of receipt of original information;
2. for NAVTEX, at the next scheduled broadcast, unless circumstances indicate the use of procedures for VITAL or IMPORTANT warnings.
3.2.1.2 Navigational warnings should be repeated in scheduled broadcasts in accordance with the guidelines promulgated in the following documents, as appropriate:
1. International SafetyNET Manual;
2. NAVTEX Manual (IMO publication no. IMO-951).
3.2.2 Manual system (HF A1A)
3.2.2.1 NAVAREA warnings should be transmitted at scheduled times. They should be repeated in the broadcast immediately following the original transmission and thereafter at least every four days for six weeks unless previously cancelled.
3.2.2.2 At least two daily transmission times are necessary to provide adequate promulgation of NAVAREA warnings. When NAVAREAs may extend across more than six time zones, more than two broadcasts should be especially considered to ensure that warnings can be received.
3.2.3 Schedule changes
3.2.3.1 NAVAREA co-ordinators should ensure that the times of HF broadcasting do not coincide with those in adjacent NAVAREAs. Times of scheduled broadcasts under the international SafetyNET service should be co-ordinated through the International SafetyNET Co-ordinating Panel.
3.2.3.2 Changes to broadcast schedules should be implemented only after the International Telecommunication Union (ITU) has been given at least three months' notice by the appropriate national authority, unless urgent operational considerations dictate more immediate action.
3.2.3.3 IMO and IHO should be informed of intended changes at the same time as they are communicated to ITU,
3.2.3.4 Arrangements should be made for informing mariners in good time of all changes
4 NAVIGATIONAL WARNINGS
4.1 General
4.1.1. There are three types of navigational warnings: NAVAREA warnings, coastal warnings and local warnings. The WWNWS guidance and co-ordination are involved with only two of them: NAVAREA warnings and coastal warnings; of the latter, only with those coastal warnings which are broadcast under the internationally co-ordinated services using NAVTEX, or in lieu of NAVTEX, international SafetyNET service, as their primary means of transmission.
4.1.2. Navigational warnings should normally refer only to the area concerned.
4.1.3 Navigational warnings should be broadcast for as long as the information is valid or until it is made available by other means.
4.1.4 Navigational warnings should remain in force until cancelled by the originating co-ordinator.
4.1.5 The duration of a navigational warning should be given in the text, if known.
4.2. The three types of navigational warnings are:
4.2.1 NAVAREA warnings
4.2.1.1 Generally speaking, NAVAREA warnings are concerned with the information detailed below which ocean-going mariners require for their safe navigation. This includes, in particular, failures of important aids to navigation, as well as information which may require changes to planned navigational routes.
4.2.1.2 Warnings for coastal areas may be provided by NAVTEX or the international SafetyNET service, when implemented in lieu of NAVTEX. From the date a NAVTEX receiver is mandatory on all ships sailing in areas of NAVTEX service (1 August 1993), it is intended that such information not be rebroadcast as a NAVAREA warning unless it is deemed of such significance that the mariner should be aware of it before entering the area of NAVTEX coverage. The national co-ordinator will evaluate the significance of the information for consideration as a NAVAREA warning while the NAVAREA co-ordinator will make the final determination (see 6.6.7 and 6.2.3 respectively).
4.2.1.3 The following subject areas are considered suitable for transmission as NAVAREA warnings. This list is not exhaustive and should be regarded only as a guideline. Furthermore, it presupposes that sufficiently precise information about the item has not previously been disseminated in a notice to mariners:
1. casualties to lights, fog signals and buoys affecting main shipping lanes;
2. the presence of dangerous wrecks in or near main shipping lanes and, if relevant, their marking;
3. establishment of major new aids to navigation or significant changes to existing ones when such establishment or change might be misleading to shipping;
4. the presence of large unwieldy tows in congested waters;
5. drifting mines;
6. areas where search and rescue (SAR) and anti-pollution operations are being carried out (for avoidance of such areas);
7. at the request of the controlling MRCC, notification of ships and aircraft on or over the open sea reported in distress, seriously overdue or missing;
8. the presence of newly discovered rocks, shoals, reefs and wrecks likely to constitute a danger to shipping, and, if relevant, their marking;
9. unexpected alteration or suspension of established routes;
10. cable- or pipe-laying activities, the towing of large submerged objects for research or exploration purposes, the employment of manned or unmanned submersibles, or other underwater operations constituting potential dangers in or near shipping lanes;
11. establishment of offshore structures in or near shipping lanes;
12. significant malfunctioning of radio navigation services;
13. information concerning special operations which might affect the safety of shipping, sometimes over wide areas, e.g. naval exercises, missile firings, space missions, nuclear tests, etc. It is important that where the degree of hazard is known, this information is included in the relevant warning. Whenever possible, such warnings should be originated not less than five days in advance of the scheduled event. The warning should remain in force until the event is completed.
4.2.1.4 NAVAREA warnings bulletins should be transmitted not less than once per week at a regularly scheduled time.
4.2.1.5 Arrangements should be made for the text of NAVAREA warnings in force to be available at port offices and, where appropriate, for their eventual inclusion in a generally available printed form.
4.2.2 Coastal warnings
4.2.2.1 Coastal warnings promulgate information which is necessary for safe navigation within a given region. Coastal warnings should normally provide sufficient information for safe navigation to seaward of the fairway buoy or pilot station and should not be restricted to main shipping lanes. Where the region is served by NAVTEX, it should provide navigational warnings for the entire IMO-approved service area of the NAVTEX transmitter. Where the region is not served by NAVTEX, it is desirable to include all warnings relevant to the coastal waters up to 250 miles from the coast in the international SafetyNET service transmission.
4.2.2.2 Coastal warnings should include, at a minimum, the types of information required for NAVAREA warnings in 4.2.1.3.
4.2.3 Local warnings
4.2.3.1 Local warnings supplement coastal warnings by giving detailed information within inshore waters including the limits of a harbour or port authority on aspects which the ocean-going ship normally does not require.
5 INFORMATION CONTROL
5.1. Message numbering
5.1.1 Navigational warnings in each series should be consecutively numbered throughout the calendar year, commencing with 0001 at 0000 UTC on 01 January.
5.1.2 Navigational warnings should, as a general rule, be transmitted in reverse numerical order on scheduled broadcasts.
5.1.3 At the beginning of every navigational warning scheduled broadcast for which there are no warnings to be disseminated, a brief message should be transmitted to identify the broadcast and advise the mariner that there is no navigational warning message traffic on hand.
5.2 Priority message handling
5.2.1 The guidelines for the handling of navigational warnings are promulgated, as appropriate, in the following documents:
1. International SafetyNET Manual;
2. NAVTEX Manual (IMO publication no. IMO-951).
5.3 Language
5.3.1 All NAVAREA and coastal warnings must be transmitted in English in the internationally co-ordinated services.
5.3.2 In addition, NAVAREA warnings may be broadcast in one or more of the official languages of the United Nations. .
5.3.3 Coastal warnings may also be broadcast in the national language, and local warnings may be issued only in the national language as a national service.
6 CO-ORDINATOR RESOURCES AND RESPONSIBILITIES
6.1 NAVAREA co-ordinator resources
6.1.1 The NAVAREA co-ordinator must have:
1. the expertise and information sources of a well established hydrographic service;
2. effective communication links with subarea and national co-ordinators in the NAVAREA and with other NAVAREA co-ordinators;
3. access to effective facilities for transmission to the entire NAVAREA. Reception normally should be possible 700 miles beyond the limit of the NAVAREA (24 hours' sailing by a fast ship).
6.2 NAVAREA co-ordinator responsibilities
6.2.1 The NAVAREA co-ordinator must:
1. endeavour to be informed of all events that could significantly affect the safety of navigation within the NAVAREA;
2. immediately upon receipt, assess all information in the light of expert knowledge for relevance to navigation in the NAVAREA;
3. select information for broadcast in accordance with the guidance given in 4.2.1 above;
4. draft NAVAREA warning messages in accordance with the IHO/IMO guidance on standardisation of texts and message drafting;
5. direct and control the broadcast of NAVAREA warning messages, making full and efficient use of national broadcast facilities in keeping with the provisions of the International Convention for the Safety of Life at Sea, 1974, as amended;
6. pass NAVAREA warnings which warrant further promulgation in adjacent areas directly to the appropriate NAVAREA co-ordinators, using the quickest possible means;
7. ensure that written copies of NAVAREA warnings likely to remain in force for more than six weeks are made available to those NAVAREA co-ordinators or national authorities requesting them. Immediate transmission by telex, facsimile, or by high-speed communications is recommended in the absence of an alternative appropriate delivery arrangement, subject to agreement between the co-ordinators concerned;
8. as soon as possible after the receipt of information concerning scheduled underwater operations as described in 4.2.1.3.10, or other scheduled operations such as in 4.2.1.3.3 and 4.2.1.3.11, pass such information to those national co-ordinators in his own NAVAREA and other NAVAREA co-ordinators who maintain a notices to mariners service covering the affected area and who have requested such information;
9. transmit periodical NAVAREA warnings bulletins;
10. promulgate the cancellation of NAVAREA warnings which contain information which is no longer valid;
11. arrange for the text of NAVAREA warnings in force to be available at port offices and, where appropriate, for their eventual inclusion in a generally available printed form;
12. act as the central point of contact on matters relating to navigational warnings within the NAVAREA;
13. promote the use of established international standards and practices in the promulgation of navigational warnings within the NAVAREA. Note: Although arrangements made by the NAVAREA co-ordinator should enable all ships to receive messages in force for an area either before reaching or on entering an area, nevertheless it should be possible, in exceptional cases, for ships to obtain, on request, texts of messages in force but not included in the current scheduled broadcasts.
6.3 Subarea co-ordinator resources
6.3.1 The subarea co-ordinator must have, or have access to:
1. expertise and information resources of a well established hydrographic service;
2. effective communication links with national co-ordinators in the subarea;
3. effective communication links with the NAVAREA co-ordinator . Note: Normally a subarea co-ordinator will serve also as a national co-ordinator .
6.4 Subarea co-ordinator responsibilities
6.4.1 The subarea co-ordinator must:
1. endeavour to be informed of all events that could significantly affect the safety of navigation within the subarea;
2. inform the NAVAREA co-ordinator of any events in the subarea which warrant the promulgation of a NAVAREA warning;
3. co-ordinate and promote the exchange of information between national co-ordinators in the subarea and the NAVAREA co-ordinator;
4. act as the central point of contact on matters relating to navigational warnings within the subarea;
5. promote the use of established international standards and practices in the promulgation of navigational warnings within the subarea.
6.5 National co-ordinator resources
6.5.1 The national co-ordinator must have:
1. established sources of information relevant td the safety of navigation within national waters;
2. effective communication links with the subarea/NAVAREA co-ordinator and adjacent national co-ordinators;
3. access to effective facilities for the transmission of navigational warnings to the region.
6.6 National co-ordinator responsibilities
6.6.1 The national co-ordinator must:
1. endeavour to be informed of all events that could significantly affect the safety of navigation within his region or national area of responsibility;
2. immediately upon receipt, assess all information in the light of expert local knowledge for relevance to safety of navigation in his area of responsibility;
3. select information for broadcast in accordance with the guidance given in 4.2.1.3 above;
4. draft coastal warnings in accordance with established international standards;
5. direct and control the broadcast of coastal warnings by a broadcast system adopted for the WWNWS;
6. arrange to receive NAVAREA warnings broadcast for his area of responsibility and, where appropriate, coastal warnings from other national co-ordinators;
7. include relevant warnings in NAVTEX/SafetyNET broadcasts and, if appropriate, in notices to mariners;
8. arrange for the texts of NAVAREA warnings and relevant coastal warnings to be available at port offices and, where appropriate, for their eventual inclusion in a generally printed form and/or notice to mariners:
9. inform the NAVAREA co-ordinator or, where established, the subarea co-ordinator of any events in his area of responsibility which warrant the promulgation of a NAVAREA warning;
10. act as the central point of contact on matters relating to navigational warnings within his area of responsibility;
11. pass coastal warnings which warrant further promulgation in adjacent regions to 1he appropriate national co-ordinators.
 
Annex 2
IMO PROCEDURE FOR AMENDING THE WORLD-WIDE NAVIGATIONAL WARNING SERVICE
 
1. Proposed amendments to the world-wide navigational warning service should be submitted to the Maritime Safety Committee for evaluation.
2. Amendments to the service should normally come into force at intervals of approximately two years or at such longer periods as determined by the Maritime Safety Committee at the time of adoption. Amendments adopted by the Maritime Safety Committee will be notified to all concerned, will provide at least 12 months' notification and will come into force on 1 January of the following year .
3. The agreement of the International Hydrographic Organization and the active participation of other bodies should be sought according to the nature of the proposed amendments.
4. When the proposals for amendment have been examined in substance, the Maritime Safety Committee will entrust the Sub-Committee on Radiocommunications with the ensuing editorial tasks.
5. The NAVAREA schedule of broadcast times and frequencies, not being an integral part of the service and being subject to frequent changes, will not be subject to the amendment procedures.
 
 
 
 
 
     
 
Radio Officer © 2002 Edition