Navtex

NAVTEX, short for Navigational Telex, is an internationally standardized automated telex system used to deliver navigational and meteorological warnings, forecasts, and other urgent safety information to ships at sea. It is part of the Global Maritime Distress and Safety System (GMDSS) and provides one-way text broadcasts intended to be received and printed or displayed on board.

Technical operation centers on MF frequencies, with international NAVTEX transmissions typically on 518 kHz and some regions using 490 kHz for national or regional services. Broadcasts are scheduled and managed by national and international NAVTEX stations, and messages are repeatedly transmitted to maximize reception. Ships equipped with NAVTEX receivers automatically select and present the relevant messages for crew review.

Message content is text-based and designed for machine processing. NAVTEX broadcasts generally include navigational warnings, weather forecasts and warnings for the area, meteorological information, and other urgent safety notices. Messages follow a standardized format with identification headers, area designations, and a content portion that can be printed on board or displayed by a NAVTEX receiver.

Coverage and limitations: NAVTEX provides coastally oriented coverage suitable for ships navigating in coastal waters and the approaches to ports. Reception depends on transmitter parameters, propagation conditions, and the receiving equipment. It is a one-way service and complements other GMDSS communications, offering a low-cost means of distributing essential safety information.

Administration and history: NAVTEX stations are operated by national hydrographic offices and coast guards, coordinated under ITU and IMO guidelines. The system originated in the 1970s and remains in routine use as a reliable broadcast method for safety-related maritime information.