Canadian Coast Guard

WORLDWIDE RADIO NAVIGATIONAL WARNING SYSTEM

(a) NAVAREA Warnings

In accordance with the decisions of the Ad Hoc Joint IHO/IMO Committee on Radio Navigational Warnings, the United States conditionally, on January 1, 1977, accepted responsibility for NAVAREAS IV and XII in the Worldwide Radio Navigational Warning System.

NAVAREA IV covers the North Atlantic Ocean West of 35°W and north of 7°N. These messages are broadcast from: Boston (NMF) at 0140 UTC on 6314, 8416.5 and 12579 FIB and at 1630 UTC on 8416.5, 12579 and 16806.5 kHz FIB.

NAVAREA XII covers the North Pacific Ocean east of 180° and north of the equator, plus the area north of 3° 25’S and east of 120°W. These messages are broadcast by Honolulu (NMO) at 0330 and 1730 UTC daily, on 8416.5, 12579 and 22376 kHz FIB.

The area warning system should normally be sufficient for the ships which proceed along the main oceanic routes of an Area. However, in some waters knowledge of the coastal warnings may prove necessary.

Subject Matter Of Warnings

The following list of messages considered suitable for transmission as warnings in this service is not exhaustive and should only be regarded as a guideline. Furthermore, it presupposes that sufficiently precise information about the items has not previously been disseminated in Notices to Mariners.

casualties to lights, fog signals and buoys affecting main shipping lanes;

the presence of dangerous wrecks in or near main shipping lanes and, if relevant, their marking;

establishment of major new aids to navigation or significant changes to existing ones when such establishment or change might be misleading to shipping;

the presence of large unwieldy tows in congested waters;

drifting mines;

areas where search and rescue (SAR) and anti-pollution operations are being carried out (for avoidance of such areas);

ships and aircraft on or over the open sea reported in distress, seriously overdue or missing;

the presence of newly discovered rocks, shoals, reefs and wrecks likely to constitute a danger to shipping, and, if relevant, their marking;

unexpected alteration or suspension of established routes;

cable or pipe-laying activities, the towing of large, submerged objects for research or geophysical exploration, the employment of manned or unmanned submersibles, or other underwater operations constituting potential dangers in or near shipping lanes;

establishment of off-shore structures in or near shipping lanes;

significant malfunctioning of radio-navigation services;

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. These should be initially promulgated by the Area Co-ordinator concerned not less than five days in advance of the scheduled event, wherever possible. The messages should be repeated as considered necessary until the event is completed.

(....)Navigational warnings broadcast within the Area should be consecutively numbered throughout the calendar year.

(c) Coastal Warnings

Coastal warnings are concerned with information listed in paragraphs (a) above which is sufficient for mariners to know when they enter a given Sub-area or region. However, coastal warnings should not be restricted to main shipping lanes.

(d) Local Warnings

Local warnings supplement the coastal system by giving detailed information on aspects which the ocean-going ship normally does not require. However, local warnings may be issued in the national language only.