Maritime weather and tide conditions – navigation equipment, radios and emergency beacons, register a 406 beacon
The Global Maritime Distress and Safety System (GMDSS) is a maritime communications system used for:
- emergency and distress messages
- vessel-to-vessel routine communications
- vessel-to-shore routine communications
If you own commercial ships with over 300 gross tonnage, or certain smaller craft, you should fit them with GMDSS equipment.
Most offshore yacht races also now insist that competing yachts are GMDSS-equipped.
Read the Merchant Shipping (Radio Installations) Regulations for more information on who has to fit GMDSS.
It's voluntary for small leisure craft to have GMDSS, but HM Coastguard (HMCG) strongly recommends that pleasure craft install GMDSS with Digital Selective Calling (DSC).
Digital Selective Calling (DSC)
Digital Selective Calling (DSC) is a tone-signalling system with the ability to include other information like:
- a vessel's identification number
- the purpose of the call
- your position
- the channel you want to speak on
A 406 megahertz (MHz) beacon can send a distress signal via satellites to alert search and rescue authorities to your location. There are 3 types:
- Emergency Position Indicating Radio Beacons (EPIRB) for ships and boats
- Emergency Locator Transmitters (ELT) for aircraft
- Personal Locator Beacons (PLB) for personal use
You must register your 406 MHz beacon with the coastguard and keep your registration up to date.
Register or update a registration
There’s no fee to register or update a registration and you can do it:
- by sending a form to UK Beacon Registry
The UK Beacon Registry
Small commercial ships should keep a listening watch on VHF channel 16 for any coastguard announcements.
If your ship needs a fixed VHF channel to receive these broadcasts, you should fit VHF DSC (Digital Selective Calling). All new vessels and all those replacing VHF radios must have VHF DSC installed.
You must mount any radio aerials as high as you can to get the best possible reception. If your main aerial is fitted to a mast, you should also provide an emergency aerial.
If you're not sure of the VHF coverage in the area where you'll be operating, contact the Maritime and Coastguard Agency (MCA).
MCA radio helpline
Telephone: 02380 329356
Find out about call charges
You must make sure that you’re able to charge the batteries that charge the ships’ radio equipment and that they’re protected from flooding.
Your fixed radio installation should be marked with:
- the ship’s call sign
- codes for the use of the radio
- Maritime Mobile Service Identity (MMSI) number (where applicable)
You should also have a card giving information on radio distress, urgency and safety procedures in full view of the radio operating position.
Navigation lights, shapes and sound signals
Your ship must comply with the requirements of the Merchant Shipping (Distress Signals and Prevention of Collisions) Regulations.
Small vessels may be exempt from certain requirements, for example if:
- you only operate between sunrise and sunset or in favourable weather, in which case you don't have to carry navigation lights
- your vessel is less than 12 metres in length, in which case you don't have to carry sound signalling equipment
The rules on navigation lights, shapes and sound signals for small commercial vessels are set out in section 17 of Marine Guidance Notice (MGN) 280 (M). Rules for other navigational equipment are detailed in section 18.
A voyage data recorder (VDR) often known as the ship’s ‘black box’, collects and stores different information over the course of a ship’s journey, including:
- the ship’s position
- audio from the ship’s bridge
- the ship’s speed and heading
- depth under the keel
- VHF radio communications
All VDRs must be tested after installation and then inspected every year.
Find out more about the requirements for voyage data recorders.
Safe navigation is particularly important in adverse weather and sea conditions.
Read more about keeping a safe navigational watch on merchant ships.
Navigation lights, shapes and sound signals
Your ship must comply with legal requirements for navigation lights and other equipment.
Read information on navigating in restricted visibility on the Maritime and Coastguard Agency (MCA) website.
Find information on controlling high-speed craft in adverse sea conditions on the MCA website.
Navigating in the Dover Strait
The Dover Strait is one of the busiest shipping lanes in the world. The Dover Strait Traffic Separation Scheme (TSS) exists to help ships crossing the Dover Strait to navigate safely and avoid collisions.
The Dover Strait and Channel Navigation Information Service (CNIS)
The Dover CNIS provides a 24-hour radio and radar service for all shipping in the Dover Strait.
Dover CNIS broadcasts information in the Dover TSS area every 60 minutes (30 minutes if visibility drops below 2 miles). You can find these on VHF radio channel 11.
Dover CNIS 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, eg cross-channel swims
Information is also broadcast about any ship that appears to be breaking the International Regulations for the Prevention of Collisions at Sea to warn other ships of a potential hazard.
Ships using the TSS are automatically tracked by radar. This information can be used in a prosecution if any ship breaks the law.
Weather information at sea
You can also get weather information from the BBC shipping forecast, which is broadcast twice a day on Radio 4.
The Met Office provides useful online information about conditions at sea, including:
- a shipping forecast and gale warnings
- marine observations which give information on wave height, visibility and sea temperature
Longer-term weather outlooks
You can get an extended outlook with information up to 5 days in advance on the 518 NAVTEX service.
Information about tides
The UK Hydrographic Office provide information on tides through the Admiralty Easy Tide Service.
You can get navigational information by radio from:
- navigational warnings, broadcast on either NAVTEX or Inmarsat SafetyNET
- NAVAREA I warnings, broadcast through EGC SafetyNET
- UK coastal navigational warnings (WZs), broadcast on VHF and MF on selected aerials at 4-hourly intervals
In-force navigational warnings are shown on the UK Hydrographic Office (UKHO) website.
Reporting navigational hazards
Contact the United Kingdom Hydrographic Office (UKHO) Radio navigational warning helpline to warn of or ask about any potential hazards.
If you're responsible for causing a navigational hazard, you'll have to contribute toward the cost of broadcasting any necessary warnings.
HM Coastguard regularly broadcasts Maritime Safety Information (MSI) by radio. MSI includes:
- information on wind strength and direction
- warnings of restricted visibility
- updates on sea conditions
- navigational guidance and warnings
MSI broadcasts may be interrupted or delayed due to search and rescue operations.
You must check MSI and other weather and tide information to avoid collisions and accidents at sea. You must also make sure that you understand any navigational guidance or warnings that are broadcast to your ship.
How to receive MSI
MSI is broadcast:
- by NAVTEX (Navigational telex) out to 270 miles
- on VHF out to 30 miles
- on MF out to 150 miles
Read the Maritime and Coastguard Agency (MCA) guide to MSI, which includes information on broadcast frequencies.