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Man talking on VHF

It has been called the “Lifeline to Land” – the VHF radio that provides for safety at sea brought bythe constant ability to communicate with land. Information important to mariners is broadcast on VHF and it allows them to remain in constant contact with the outside world.
The VHF phone is international. It was originally developed to meet the needs of commercial shipping for ship-to-shore and ship-to-ship radio communication in coastal waters. VHF radio may now be used on recreational craft according to the same rules.

VHF is used by all merchant vessels, ferries, fishing vessels, large oil tankers and the navy. VHF radio is used all over the world as the best and most reliable communication system at sea.

Three important functions

Distress radio
A functioning communication system may prove invaluable if you break down, are wrecked or if someone onboard needs medical assistance. In an emergency, VHF is the best choice so that you can always call for assistance quickly.

Mayday calls
VHF radio makes it possible for you to contact the Maritime Rescue Coordination Centre any time on the Mayday Channel 16. A mayday call on channel 16 is also heard by other boats and ships in the area that can assist if needed.

The VHF radio can also be radiolocated. By calling two neighbouring stations you can determine your position through cross bearing. See the paragraph on VHF radiolocation below. Locator receivers are also found on many maritime search and rescue units, enabling the vessels to find a vessel in distress even in the dark or fog.

Medical assistance
If someone on board has an accident or becomes ill, you can always get advice and assistance from a doctor via VHF radio. The doctor can assess the need for medical care: is oral advice enough? Should you head for port, or should the victim be picked up by a search and rescue team? Communication via VHF makes rapid intervention possible.

Communications radio

You can use a VHF phone to talk to other recreational craft equipped with a VHF phone. You can talk to pilot boats, the Coast Guard, police boats, maritime search and rescue cruisers and other vessels in commercial traffic. You can also talk to facilities on land, such as ports and bridge guards.

Phone calls via VHF
You can order ship-to-shore phone calls via coastal radio stations. This allows you to call home to family and let them know how you are – and please remember to do that. The Maritime Rescue Coordination Centre receives many calls during the summer from worried relatives who have not heard from their loved ones as agreed. You can easily avoid those situations by using a VHF phone.

Information and warnings

Stockholm Radio broadcasts traffic lists, navigational warnings and weather reports via VHF regularly throughout the day. The coastal weather reports produced by SMHI are specially designed for mariners in coastal waters and are very detailed. The navigational warnings contain all information important to mariners, such as notice of an unlit light or drifting timber. If something exceptional takes place between regularly scheduled broadcasts, Stockholm Radio broadcasts the information immediately.

The main advantage of VHF is that it is an open system. Everyone can hear everyone else and you do not need to know any phone numbers to reach a VHF station.

Mobile phones
Mobile phones work relatively well inside the archipelago and in coastal waters, but signal strength is less reliable further out to sea. They are excellent for ordinary phone calling, but do not have all the advantages of VHF.

Mayday calls

Mayday calls are reserved for true emergencies, that is, when there is immediate risk of loss of property or life. Use the following procedure to make a Mayday call:

Mayday, Mayday, Mayday
This is the vessel _________, I repeat, this is the _________, again, the _________ (state the name of your vessel three times).

Mayday, the vessel _________, and call sign (state one time). State your position and the nature of your emergency and need for assistance.

Make the call on Channel 16. Response to Mayday calls is in the following order:

First, wait for a response from the Maritime Rescue Coordination Centre (MRCC).

If the MRCC does not respond, other vessels, base stations or other land stations should respond to the call.

As long as the Mayday situation is ongoing, other vessels are required to stay off the radio on Channel 16. This remains in force until the MRCC cancels the Mayday silence by broadcasting (“Silence fini”) Note: “Silence” in this context is pronounced as in French “Seelonce.”

Pan calls

Pan calls (prounouced “pahn”) are used when the vessel or people are in trouble or ill but there is no immediate danger to life.

Start the call with:
PAN-PAN, PAN-PAN, all stations, all stations,
this is the vessel _________. State the reason for the Pan call and the desired assistance.

The call should be made on Channel 16. You may thereafter be instructed to use a different channel.

Securité messages

Securité messages are broadcast on Channel 16. Start the call with:
Securité, Securité, Securité

Securité messages are used to report navigational safety concerns or weather warnings. They are broadcast by Stockholm Radio and are provided at the beginning of each broadcast of weather forecasts, gale warnings and navigational warnings. They are broadcast on the traffic channels as shown on the table.

VHF radiolocators

Recreational craft equipped with a VHF phone can get assistance with determining position from land-based VHF radiolocator stations and vessel units belonging to thehe Swedish Maritime Administration, the Swedish Life Saving Society and the Swedish Coast Guard.
Call the appropriate station or vessel unit. When the person on duty responds, switch to the channel he or she instructs and call again on that channel and request radiolocation. The corresponding station reads the bearings from the land station/vessel unit to the boat while listening to the transmission from the boat. It is also important in this context to request the station or unit’s position.

The stations/vessel units have various ranges depending on antenna height. Cross bearings are possible if there is more than one station/unit in the vicinity.

Call the next station/unit in the vicinity and repeat the same procedure. Mark the bearings from the two stations/units on your chart and ascertain the positions of the stations/units. The intersection between the two bearings shows the current position.

The precision of the stated bearings is usually 2 à 3º over open water. The best results of cross bearings are obtained if the angle between the bearings is as close to 90º as possible.

Radiolocation should be requested only to ensure the safety of the boat and crew so that you do not unnecessarily burden duty personnel.

Training is required

In addition to commercial vessels, some 20,000 recreational craft are currently equipped with VHF. In addition to the communications capacity of the system VHF is also an international distress and safety system so there are certain rules that must be followed by everyone who has VHF or is thinking about getting it.

Certificate required to use VHF
In order to obtain a limited radio telephony certificate (of the SRC/Short Range Certificate type), you must take a written examination given by a test examiner appointed by the NFB (The Swedish Council for the Education and Training of Yachtsmen, +46 8-663 79 93). The examination takes about 30 minutes and covers questions on regulations, Mayday, Pan and Securité calls, the phonetic alphabet, radio traffic discipline, communication and more. The certificate is international and does not expire. It costs SEK 200 to take the VHF certificate examination.

Permit required to use VHF
The Swedish National Post and Telecom Agency (PTS) is the state agency responsible for issuing permits and keeping permit registers, including those for VHF. VHF permits state the boat’s call signal, sel-call if applicable and the station manager’s name.

The certificate and permit should always be kept onboard so that you can show it to an official agency upon request. The annual permit fee is SEK 135.

A subscription is necessary in order to have access to all coastal radio services. Subscriptions are available from Stockholm Radio, which is run by Viamare. You must have a subscription to fully use your VHF and gain access to all services provided by Stockholm Radio and foreign coastal stations.

It is easy to apply for a subscription. Simply contact Customer Service at Stockholm Radio, which can also answer other questions pertaining to VHF.

GMDSS – The new Global Maritime Distress and Safety System

Special procedures and equipment apply worldwide for sending distress alerts to Maritime Rescue Coordination Centres. The system is called GMDSS (Global Maritime Distress and Safety System) and it includes specificaly required equipment for commercial shipping. The requirements are different for different types of waters, but certain equipment is considered mandatory for all commercial vessels.

EPIRB, NAVTEX, SART, VHF-DSC and PORTABLE VHF are mandatory in commercial vessels for coastal navigation. Deep water shipping is also required to have MF/HF-DSC and Inmarsat.

NAVTEX is used for receiving navigational warnings and weather information.

EPIRB (Emergency Position Indicating Radio Beacon) is an emergency transmitter whose signals are received by satellites. The receiver can be geographicaly positioned and also provides information about the vessel’s identity.

SART (Search and Rescue Radio Transponder) is a small, battery-operated transponder that produces an echo on ship’s radar.

Consequences for on recreational boating
A large number of recreational craft already have VHF radio onboard. They will be used exactly as they were in the past and the open monitoring of Channel 16 will continue on land and onboard commercial vessels until further notice. When purchasing new equipment, however, you should select a VHF radio with DSC.

What is DSC?
DSC (Digital Selective Calling) is an internationally developed automatic distress alert system. In simplified terms, one can say that the manual voice call on Channel 16 or a traffic channel is replaced with a brief burst of data signals on a special channel (70).

The call is coded so that identity information appears as a 9-digit number, known as the MMSI. MMSI is essentially your VHF radio’s “phone number.” You can use DSC to send addressed calls, but distress alerts have a special status – they are not addressed, but are directed at everyone. A distress alert contains the boat’s MMSI, position and time, as well as the type of distress.
To send a distress alert, you push the key combination that generates distress alerts. If the radio is not connected to a navigator, you will have to key in your position manually. Once the distress alert has been sent out, the land system will decode and display it on land and send back a confirmation. The VHF station then switches automatically to Channel 16 for continued radiotelephone traffic.

DSC can also be transmitted on MF frequency 2187.5 kHz and on a number of HF frequencies.


DSC = Digital Selective Calling.
EPIRB = Emergency Position-Indicating Radio Beacon. Floating radio buoy for distress alerts via satellite.
GMDSS = Global Maritime Distress and Safety System. International radio safety system.
Ls = Pilotage station
NAVTEX = System for broadcasting safety information to vessels at sea, MSI (Maritime Safety Information)
MF = Medium Frequency (300 – 3000 kHz).
MMSI = Maritime Mobile Service Identity code. Identity number/call signal.
MRCC = Maritime Rescue Coordination Centre.
SART = Search And Rescue Transponder. Transponder buoy that produces an echo on radar.
SRC = Short Range Certificate. Restricted radiotelephony certificate.
VHF = Very High Frequency (30 – 300 MHz).
VTS = Vessel Traffic Service.

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