VHF Home Learning

Types of Calls we will be making:

Routine Calls:

The key phrase with routine calls is “Ships related Business”. Where to meet for lunch, eta, the Marina you are meeting at, needing a hand with an issue on the vessel, fuel stops etc. are all part of the day to day running and navigation of the vessel. Subjects such as discussing the football is not.

Routine calls use Channels 6, 8, 72 and 77. When we are operating in a routine manner, we use the lowest power setting for transmission, so we only cover the smallest area for communication.

Non-DSC (Digital Selective Calling) routine calls start on Channel 16 then move to a working channel (such a 6, 8, 72 and 77) as soon as possible. The caller / initiator chooses the working channel, the reason for this is the initiator will have checked that the channel they are going to have their routine call on is clear and not in use by other users (It takes about 2 minutes of listening prior to use)

DSC routine calls include an option for selecting the channel as part of the call set-up. This channel is then used by each radio ready for the call as part of the digital call set-up. This negates the use of channel 16, which works well for when there is a MAYDAY or Silence has been initiated on Channel 16. The requirement for using the DSC side of the radio is the knowledge of knowing the MMSI of the other vessel you wish to have the routine call with.

Be aware that the Coastguard and some other stations such as port authorities will dictate the working channel regardless of what is suggested by the caller.

For routine calls with some vessels, they may use pre-nominated channels for communication, e.g. large ships may wish to use channel 13 for bridge to bridge.

Safety Calls – Proword “SECURITAY” (how you actually pronounce it!), is used for navigational and weather warnings.

Safety calls are addressed to “all ships” or “all stations” this is decided by the sender as to which is most appropriate. This is most commonly used by the Coastguard or port authorities to report events such as strong wind warnings and hazards such as floating debris in shipping channels or large vessel movements. Anyone can send a Safety call if it is appropriate and needed.

Urgency Calls – Proword “PANPAN”, used for non-emergency requests such as mechanical breakdown. There must be no threat to life, or imminent danger to the vessel.

Urgency calls must be addressed to someone, “all stations” is the most common so this is directed at both maritime craft, land stations and aircraft listening on the maritime frequencies at that time. It should contain the reason for the call, for example a boat that has broken down and be looking for a tow, or a crew member is feeling sick and you need permission to give them some medication on board the vessel.

Distress Calls – Proword “MAYDAY” DSC Distress Alert sent using the dedicated Distress button.

The internationally accepted definition of a distress situation is:

Grave and imminent danger to you/your life, vehicle, vessel, or aircraft. Immediate assistance is required. Distress calls are made by the station that the Distress situation is happening to. All Distress working transmissions start with the proword “Mayday”. The Coastguard will use the prowords “Mayday Seelonce” to clear a channel for distress working, and “Mayday Finee” when distress working has ended.

The Distress Call:

This is the Distress call for a motorboat called “Flam” with unique call sign MABC8 and MMSI 232004876. To aid clarity it is a good idea to have radio procedure cards by your radio including a template distress call. The MCA frequently have waterproof procedure stickers available for free on their website.

It may help to use the following acronym to ensure all information is included in the distress call: – MIPDANIO
M ayday
I dentify yourself – Name, Call sign and MMSI number
P osition – Either latitude and longitude, or distance and bearing from a known landmark e.g. half a mile N of Cowes
D istress type – e.g. fire, sinking, medical threat to life, etc.
A ssistance – Immediate assistance required
N umber of people on board and any special requirements. Remember to include yourself!
I nformation – Any other relevant information e.g., lifejackets are worn, life raft onboard, setting off flares etc.
O ver.

Mayday Example:

Mayday, Mayday, Mayday
This is Motor Vessel Flam, Flam, Flam Call sign MABC8 MMSI 232004876 Mayday Flam Call sign MABC8 MMSI 232004876 In position 50°42.07′ N 001° 12.42′ W
Fire on Board
I Require Immediate Assistance Eight Persons on Board Abandoning To Life Raft

Urgency Call:

The use of a Pan-pan in radiotelephone communications is to signify there is urgency on board a boat, ship, aircraft, or other vehicle but that, for the time being at least, there is no immediate danger to anyones life or to the vessel itself. Again, to avoid having to memorize the call sign, MMSI number or overall format a radio procedure card near the radio is recommended.

Pan-Pan Example:

Pan-Pan, Pan-Pan, Pan-Pan
All stations, All Stations, All Stations This Is Sailing Yacht Dab, Dab, Dab
Call Sign M4GHQ MMSI Number 235899983
My Position 51°44’.71N 001°04’.32E
I Have an Injured Crew Member and Request Medical Advice Over

Procedure for the radio:

When working on the radio and giving you position, numbers are split up. For example
51°44’.71N, when being spoken on the radio it becomes – Fife one Degrees, four for minutes decimal seven one north

Maday Relay:

This is something that may be done by yourselves for something you see, of come across on your voyage. This is something that has happened to someone else!

Mayday Relay Example:

Mayday relay, Mayday relay, Mayday relay.
This is Sailing yacht Ding, Ding, ding,
Call Sign 2TWAT MMSI 235854235
Mayday Person in the water
Approximately half a mile due west of our current position of 51°44’.71N 001°04’.32E
They Require immediate assistance
They are wearing a life jacket
We are proceeding towards them


UK VHF Channels and Usage:

In the United Kingdom there are approximately 57 VHF channels available on your radio plus the private channels for use by yacht clubs and emergency services / specialist maritime users. 3 channels are dedicated to digital data, Channel 70 for DSC data and 2 channels for Automatic Identification System services (AIS).

The UK uses the “International Frequency” system, used by virtually all other countries in the world. In the UK we have designated the use of most of the channels when working inside UK territorial waters. Other countries may use the channels for different purposes. Channel 16 remains the only constant throughout the world for its designation and use.

Distress, Safety and Calling Channels:

Channel 16 – Distress, Safety & Calling Channel 16 is the international distress, safety and calling radiotelephony channel. Where it is necessary to call a station on Channel 16, other than in cases of Distress or Urgency, both stations should switch to an alternative channel as soon as possible. All calls on Channel 16 should be kept brief and should not exceed one minute, when not concerning distress, urgency, or safety.

For a call between ship stations an inter-ship channel should be used, such as Channels 6, 8, 72 or 77. For a call to a coast station the station’s assigned channel should be used e.g., Southampton VTS – Channel 12.

Channel 70 – Digital Selective Calling:

All DSC (Digital Selective Calling) alerts are sent via digital data transmissions on Channel 70 by the radio equipment once the relevant buttons have been pressed. This digital data allows additional information such as the vessel name, radio MMSI and position to be received by DSC capable radios adding an extra layer of functionality.
It must not be used for voice communications. Most Modern radios will not allow transmission on this channel.

It is strongly recommended that any newly purchased equipment be DSC equipped.

Channel 13 – Bridge to Bridge:

This channel is used for bridge-to-bridge voice communications under GMDSS. It will normally be monitored by commercial vessels if a danger of collision exists. This channel is one of the few, under GMDSS that can be used without a preceding DSC alert on Channel 70.

Channels 6, 8, 72, 77 – Inter-ship:

Inter-ship channels are for communications between ship stations. Routine communications should be restricted to Channels 6, 8, 72 and 77. However, if these are not available, the other channels in the chart in the book, marked as being available for inter-ship working, may be used.

Channels 11, 12, 14 – Port Operations:

Certain channels have been set aside, by international agreement, for use in the Port Operations and Ship Movement services. These are assigned to a user, such as a port or oil terminal where the safe movement of ships is important. The channels assigned to specific users are published in the Admiralty List of Radio Signals. It is important not to use these channels for other purposes if they have been assigned locally or if they have not been set aside for inter-ship working.
Be aware that some Harbour masters and smaller ports use other channels for port operations as listed in the almanac or online.

Channels 15, 17, 75 and 76 – Guard Channels:

These frequencies are either side of Channel 16’s frequency. To prevent interference on Channel 16 these channels are restricted to low power (1w) for transmitting. 15 and 17 are designated for on board working, 75 and 76 are designated for port operations and should only be used at the request of the port authority. The restriction to 1W reduces the Bleed through from these channels to channel 16 if the radio is not quite perfect on the frequency of transmission.

Channel 67 – UK Small Craft Safety:

Used by HMCG as a small ship safety channel in the UK only. For routine communications, i.e. anything not related to distress working, this channel should be used to contact the Coastguard directly without using Channel 16. (this is a Solent area ‘thing’, for outside of the Solent you will need to use 16 then move to 67)

National Coast Watch:

Channel 65 has been allocated to the national cast watch, this is a useful service for radio checks and finding out weather if you have missed the Coastguard broadcast
Private & Marina channels:

These channels have been set aside by the United Kingdom administration, for matters relating to mooring, berthing and race control. This are often M1 / M2 or P1 / P2 depending on the manufacture of the radio. NB – These channels are for the UK territorial waters only not for use when you voyage out of these waters.

Channel 80:

Channel 80 is used for contacting marinas in the UK. Most UK marinas can only be contacted on this channel as shore-based radio licenses are issued on a channel-by-channel basis and require the licensee to pay an annual fee for each channel used. Any variation on this is listed in the almanac or online.

Channel 80 is a duplex channel, meaning it has two separate frequencies, one for outgoing and one for incoming transmissions. Type D radios can only receive one of these frequencies, meaning that only one side of the conversation is heard. For this reason, take at least a minute to ensure that the channel is not in use before transmitting.

Channel M and M2:

Channels M and M2 are UK channels and should only be used in UK territorial waters.

They are used by sailing clubs for race control and safety communications. As they are usually used by shore-based radios as well as ship-based radios and therefore incur an annual fee their use is restricted to the club that hold the license.

Channel M1 may be shown as P1 or 37A depending on the radio equipment. M2 may be shown as P2.


Further information:

The channels between 29 – 59 are private channels for specific licensed use, e.g., by the RNLI or Coastguard. Radio equipment needs to be reprogrammed to receive these channels and users need to hold a license specific to the channel being used. Unauthorized access to these channels can be subject to a fine from Ofcom for breach of licensing.

Channels 00 and 0 are used exclusively by search and rescue and emergency services in the UK, and similarly to channels 29 – 59 radios should only be able to access channels 00 and 0 if properly authorized and licensed to do so. Again, unauthorized use is illegal and may be subject to a fine from Ofcom.


Radio operation and authorization of use:

Radio use is authorized by the master of the vessel. Radio communications are also subject to secrecy and cannot be transmitted or recorded by public.


VHF Performance:

The range of VHF radio communications does not come first and foremost from the device power but above all from the position height of the transmitters and receiver’s antennas. Of course, it is compromised by the terrestrial curvature and interposed obstacles.

The calculation is easy: for each antenna, the communication range (to the horizon) is 2.5 times the square root (SQR) of the antenna height. The communication range between two antennas is the sum of the two results.

Power can be used to improve the quality of signal and to overcome some obstacles. Remember, more power out means more power in, giving shorter battery life for handhelds or non-recharging batteries. Always start with the lowest power setting and work up. All fixed sets have at least two power settings, 1 watt and 25 watts. With power setting comes the limitation of signal strength. For example, 1 watt can travel up to 10nm before the signal loses strength with 25 watts traveling up to 60nm before the signal become to degraded by the atmospheric interference.

Because VHF travels in straight lines, like light, as you travel away from land the curvature of the earth prevents the signal from reaching you. This happens between 35 and 50 miles offshore and if you still need to communicate over that distance you need to look for some other way of achieving this.


Some pro words and their meanings:

Acknowledge: Use this when the person you are addressing must acknowledge receipt of the message.
Affirmative: This means Yes, or that is correct.
Break Break: You have an urgent message and need to interrupt the current conversation
Correction: Indicates that an error has been made and that the transmission will repeat from the last word correctly used.
I say again: I will re-transmit the message, or part of the message
I spell: The word will be spelled using the phonetic alphabet
Negative: No, or that is not correct
Out: End of transmission – no reply is expected
Over: Means it is the end of transmission and a reply is expected.
Radio check: what is my signal strength and readability?
Relay to: Transmit this message to the addressee indicated
Roger: Message received and understood
Say again: Please repeat your last transmission
Station Calling: Unknown station calling you to allow designation of unknown station.
This is: Indicates the calling unit’s identification is next. For instance, if dispatch were making a call and needed to identify themselves, they would say “This is dispatch”
Wait: A pause of a few seconds follows
Sécurité: This is a marine safety alert and is normally repeated 3 times.
Pan Pan: This is an urgent call requesting help and is also repeated 3 times.
Mayday: This is an emergency distress call that overrides all other communications and general etiquette is to keep the channel clear until the event is cleared.


Types of licences:

Ships Radio Licence:

The Ship Radio Licence authorizes the installation and use of maritime radio and associated equipment, as well as non-maritime radio equipment (such as a mobile / satellite phones) on a named ship, subject to applicable licence conditions. The ship must be registered in the UK or one of the Crown Dependencies to be registered with Ofcom.

This covers:

MF, HF and VHF equipment (including DSC);

Satellite communications equipment;


Search and Rescue Radar Transponders (SARTs);

UHF equipment for on board communications equipment;

EPIRBs and PLBs;

MOB devices;

AIS SAR Transmitters;

and ESOMPs and Earth Stations

Ships Portable Radio licence:

The Ships Portable Radio Licence authorizes the use of one piece of portable maritime equipment from each of a limited number of categories of equipment, including an EPIRB/PLB/VHF handheld radio etc. Unlike the Ship Radio Licence, it does not restrict use to a single ship. It therefore allows equipment to be taken from one ship to another. It might typically be used by weekend dinghy sailors or kayakers or those who cruise canals.

As a side note this licence is restricted to only UK territorial seas only.


Knowledge test:

Please complete and bring with you on your course and this will be gone through with your instructor on the first morning of the course.

Q1 – You are currently working as a dinghy instructor in the UK, and you have bought yourself a Handheld VHF for your buoyancy aide. What licence would you need to have to possess that radio?

Q2 – you are the race officer at the Royal Commodore Yacht Club in Gosport, you are going to be communicating with the Fleet of yachts about the racecourse and where the marks are. In your instructions to the race skippers what channel would you choose and why for Race communications amongst the fleet?

Q3 – You hear your boat name called on the radio, but you cannot hear the Stations name who is calling you, what pro word would you use to call the unknown station back with and how would it be worded? Write out your response for the communication you would send below

Q4 – you are on a Fishing boat called “Breaking Bass” and your crew mate has broken his arm. You are in position 50˙49’.85N 001˙20’.75W. your MMSI is 235897546 with your call sign of M3TH5. You have life jackets, life raft, flares, and are still in a fully working boat. There are 5 of you on board in total.
What call would you send out? Write below your call you would make, including what channel you would send it out on.

Q5 -you are on a sailing vessel called “Ship Happens” and you have run aground on “Look out sands” by Plymouth Harbour entrance. You have noticed that the boat is taking on water and there is a crack developing along the keel bolt matrix. With current weather deteriorating and sea state getting worse. Your position is 49˙27’.85N 004˙08’.89W, MMSI number 232461276 Call Sign W4T3R. You have no lifejackets, but you do have a life raft, you are there with your Partner and family.
What DSC alert would you send out and what Voice message would go with this?

Q6 – you are a motor vessel “water U Looking at” and have spotted a load of tree stumps floating down Southampton water, you had to take evasive action to avoid hitting them and sinking your boat. Your MMSI is 234754297 your Call sign is “6UNH0”, when you took evasive action you were in position 50˙59’.10N 001˙34’.88W, the Stumps are drifting with the tide in a South Easterly Direction. They are in an area about 30m in width and 45m in length and pose a serious navigation risk to shipping.
What DSC Alert would you send, and what voice message would go with this? Write it out below.

Q7 – you are a motorboat called “Knot 2 Bad” you have got a line wrapped around your prop. Your position is 49˙59’.85N 001˙23’.23E, outside Brighton Marina. There are 4 POB, MMSI 235879541 Call Sign “0I1D0”
Write out the voice message you would send, and which DSC alert would you select?

Q8– you are a fishing trawler “Master Baiter 2” your skipper has suffered a heart attack from over-exertion. Call sign “1DI3T” MMSI 235798465, your Position is 48˙51’.84N 000˙20’.01W, you have 6 people on board, with Lifejackets, Life raft and flares.
Write out the call you would send with the DSC alert Selection you would make.

Q9 – you are sailing along in your vessel called “no Worries” as you sail past Yarmouth you come across a Kayak with no one on board, when you come along side it you see it looks new, with kit on board, a dry bag with someone’s wallet and keys, with some bought sandwiches that are still in-date. On the hull you see its name plate “Sotally Tober” you are in position 50˙13’.26N 001˙39’.89W your MMSI is 235130875 Call Sign “C41L5” it is 1454 when you find the Kayak
What Voice message would you send and on what channel? Write it below.