Home UK Rules Boating Maritime and Work at Sea › Navigational Guidance
Maritime Navigational Safety Warnings

As a ship owner, there are several ways you can receive navigational guidance and warnings. For example, the UK Hydrographic Office use radio to give out warnings relating to navigational hazards.

This guide overviews safe navigation in adverse weather and sea conditions. Check if your ship complies with the navigation equipment requirements for small commercial vessels.

Navigational Guidance and Radio Warnings

UK seafarers, crew, and ship owners can get various types of navigational information by radio via:

  • Navigational warnings (broadcast by the Maritime and Coastguard Agency on NAVTEX or Inmarsat SafetyNET).
  • NAVAREA (I) warnings (broadcast through EGC SafetyNET).
  • UK coastal navigational warnings (broadcast on VHF and MF on selected aerials at 4-hourly intervals).

The UK Hydrographic Office (UKHO) website provides Radio Navigational Warnings (RNWs) and UK coastal warnings. It lists all in-force NAVAREA 1 and UK Coastal Warnings (WZs).

Note: A leaflet produced by the Maritime and Coastguard Agency (MCA) gives extra details on maritime safety broadcast times and for medical advice calls.

Receiving Reports on Navigational Hazards

As part of maritime navigational guidance and safety warning you should get radio warnings about:

  • Areas to avoid where anti-pollution or search and rescue activities are taking place.
  • Broken or damaged lights, fog signals, buoys or other navigational aids that may affect main shipping lanes.
  • Cable or pipe laying, naval exercises, or underwater operations that may be a danger for shipping lanes.
  • Drifting hazards (e.g. derelict ships, icebergs, mines).
  • Problems with radio navigation, radio, or satellite maritime safety information services.
  • Unexpected closures of, or changes to, established routes.
  • Wrecks, reefs, rocks, and fish shoals that could be a danger to main shipping lanes.

If you spot any of these hazards yourself while at sea you can contact the United Kingdom Hydrographic Office Radio navigational warning helpline.

UKHO Radio Navigational Warning Helpline
Email: [email protected]
Telephone: 01823 353 448

Note: Being responsible for causing a navigational hazard means you would need to contribute toward the cost of any broadcasts of obligatory navigational warnings (where necessary).

Safe Navigation at Sea

Navigating safely at sea is especially important in adverse weather and sea conditions. MCA guidance MGN 315 (M) provides further information on keeping a safe navigational watch on merchant vessels.

Navigating in the Dover Strait

One of the busiest shipping lanes in the world is the Dover Strait. See the Dover Strait Traffic Separation Scheme (TSS). It exists to help ships crossing the Dover Strait navigate in a safe manner and to avoid collisions.

Navigation Lights, Shapes, and Sound Signals

Ships must comply with requirements for navigation lights and other equipment. MSN 1781 Amendment 2 outlines changes to annex IV of the convention on the international regulations for preventing collisions at sea, 1972 (COLREGs).

Navigating in Restricted Visibility

Maritime and Coastguard Agency (MCA) guidance MGN 369 gives further information describing the proper conduct of vessels in restricted visibility.

Controlling High-Speed Craft

High-speed craft can suffer some degree of difficulty in following and quartering seas. Often, it can include behavioural activities such as bow diving, broaching, and surfing.

Note: Read MGN 328 for extra details on the control of a high-speed craft during adverse sea conditions.

Channel Navigation Information Service (CNIS)

The Dover CNIS provides a 24-hour radio and radar service for all shipping in the Dover Strait. They relay information in the Dover TSS area every sixty (60) minutes (30 minutes if visibility drops below 2 miles). You can get the broadcasts on VHF radio channel 11.

The Dover Strait Channel Navigation Information Service broadcasts information on:

  • Weather and sea conditions
  • Navigational hazards, like hampered vessels
  • Misplaced or defective navigational aids
  • Deep draught bulk carriers and tankers
  • Vessels under tow
  • Surveying vessels
  • Unorthodox crossings (e.g. cross-channel swims)

Transmissions may also include information about any ship that appears to be breaking the International Regulations for the Prevention of Collisions at Sea. This service helps to warn other ships in the vicinity of any potential hazards.

The system uses radar to automatically track ships using the TSS. The authorities can use this information in a prosecution if any ship breaks maritime laws in United Kingdom.

Navigation Equipment (small commercial vessels)

Small commercial ships should keep a listening watch on VHF channel 16. This radio channel allows you to receive coastguard announcements.

Some ships may need a fixed VHF channel to receive these broadcasts. If this is the case, you should have VHF DSC (Digital Selective Calling) fitted.

Note: All new vessels must have VHF DSC installed (and any that are replacing outdated VHF radios).

Radio Installation Regulations

Mount radio aerials as high as possible to get the best reception. You should also provide an emergency aerial in cases where the main aerial is fitted to a mast.

You can contact the Maritime and Coastguard Agency (MCA) if you are unsure of the VHF coverage in the area of your operations.

MCA Radio Helpline
Telephone: 02380 329356
More on phone call charges.

Making sure you can charge the batteries that charge the radio equipment of the ship is a requirement. You must also ensure they have adequate protection against flooding.

A fixed radio installation should contain certain identification markings that show:

  • The call sign of the ship
  • Codes for the use of the radio
  • Maritime Mobile Service Identity (MMSI) number (if applicable)

Note: You should also have a card that provides clear information on radio distress, urgency and safety procedures. The card should be in full view of the radio operating position.

Navigation Lights, Shapes and Sound Signals

Details above show the international regulations for preventing collisions at sea, 1972 (COLREGs). Even so, some small vessels may be exempt from certain requirements, such as if:

  • You only operate between sunrise and sunset (or in favourable weather). In this case, you would not need to carry navigation lights.
  • The vessel is less than twelve (12) metres in length. In this case, you would not need to carry sound signalling equipment.

Note: MCA guidance notes MGN 280 (M) contains further information on construction standards for small vessels in sport use. It also advises how the standards of the SCV code may be used for already coded vessels.

Maritime Navigational Safety and Warnings in United Kingdom