4.1 General
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1288/Rev.1 – Amendments to Resolution A.706(17) – World-Wide Navigational Warning Service – (24 June 2013) - Annex 1 – IMO/IHO World-Wide Navigational Warning Service Guidance Document - 4 Navigational Warnings - 4.1 General

4.1 General

  4.1.1 There are four types of navigational warnings: NAVAREA warnings, Sub-area warnings, coastal warnings and local warnings. The WWNWS guidance and coordination are involved with only three of them:

  • .1 NAVAREA warnings;

  • .2 Sub-area warnings; and

  • .3 Coastal warnings.

  4.1.2 Navigational warnings should remain in force until cancelled by the originating coordinator. Navigational warnings should be broadcast for as long as the information is valid; however, if they are readily available to mariners by other official means, for example in Notices to Mariners, then after a period of six weeks they may no longer be broadcast.

  4.1.3 The minimum information in a navigational warning which a mariner requires is "hazard" and "position". It is usual, however, to include sufficient extra detail to allow some freedom of action in the vicinity of the hazard. This means that the message should give enough extra data for the mariners to be able to recognize the hazard and assess its effect upon their navigation.

  4.1.4 If known, the duration of the event causing a navigational warning should be given in the text.

  4.1.5 Some of the subjects for navigational warnings listed in paragraph 4.2.1.3 (e.g. drifting ice and tsunami warnings) may also be suitable for inclusion in METAREA forecasts or warnings. In this event, appropriate coordination between the relevant NAVAREA and METAREA Coordinators must occur.

Parent topic: 4 Navigational Warnings
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