"Radio Navigational Warnings" represent the navigational warnings which have to be urgently brought to the attention of mariners.

The following warnings are subjects worthy of being transmitted in the form of NAVAREA warnings:

  • Damage to lights, fog signals and buoys on the main waterways;
  • presence of dangerous wrecks in or near the main waterways and, if possible, their marking;
  • Installation of new aids to navigation or significant changes to the existing ones when they could negatively affect the deroulement of navigation;
  • Presence of trilers in the crowded waters even if they are not too large;
  • Drifting mines;
  • Areas where there are search and rescue operation of aircraft damaged or missing;
  • At the request of Maritime Rescue Coordination Centre (MRCC), announcement about vessels and planes damaged or missing;
  • Presence of rocks, banks, reefs and wrecks newly discovered as being hazardous to navigation and, if possible, their marking;
  • Unexpected change and cancellation of the established routes;
  • Activities of cable or pipe installing, towing of large submerged objects used for search or exploitation, using of guided or radiocontrolled submersibles or operations representing potential hazards on / or near the waterways
  • Installing of the offshore buildings located on / or near waterways;
  • Malfunction of the radio navigation service, the land navigation informing service and the satellite service;
  • Information on the specific operations which may affect the safety of navigation, even on the large areas. For example, military exercises/firing, space missions, nuclear tests etc. Where it is known the danger degree, it is important the related information to be included in the respective warning. Whenever possible, such information must be submitted at least 5 days before the planned activity. The warning will remain in force until the completion of this activity;
  • Acts of piracy and armed attacks on the vessels(only in accordance with the requirements of the international code for shipping security and port facility)

The list is not complete and can be used as a source of information. Moreover, this implies that very accurate information was not previously announced through the notices to mariners.


Radio Navigational Warnings (RNWs) are published by Maritime Hydrographic Directorate and internationally promulgated by NAVAREA III.