VHF Marine Radio Home Learning

VHF Marine Radio: Essential Guide for Safe Boating

VHF marine radio is critical for safe communication at sea. This guide prepares you for the RYA VHF/SRC course, covering 9 key aspects: call types, UK channels, handheld vs. fixed radios, and licensing. Learn to use VHF marine radios confidently for routine operations and emergencies.

Key Insights: Master routine, safety, urgency, and distress calls; understand UK VHF channels; choose the right VHF marine radio; and secure proper licensing.

Next Steps: Complete the knowledge test and review with your RYA instructor.

A VHF marine radio ensures reliable communication on the water.

What is a VHF Marine Radio?

A VHF marine radio enables reliable, short-range communication for boaters. It’s used to coordinate with vessels, contact marinas, or reach the Coastguard(https://www.gov.uk/government/organisations/maritime-and-coastguard-agency). Unlike mobile phones, VHF marine radios are designed for marine environments, using standardized frequencies for clear, long-distance communication. Every boat, from skiffs to yachts, should have a VHF marine radio. It’s essential for daily tasks like arranging berths and critical for emergencies, acting as a lifeline. Learn more about RYA training courses(https://commodore-yachting.com/sailing-courses/) to master its use.

Why VHF Matters: More Than Just a Radio

Whether you’re planning an afternoon paddle, a coastal cruise, or embarking on a week-long sailing adventure, a VHF marine radio is as vital as a lifejacket. It serves as your direct link to other boats, harbors, and emergency services—especially when mobile signal drops off just past the marina wall. If you’re serious about improving your seamanship—whether you’re aiming to bolster your confidence before a club race or start a career on the water—solid radio skills are essential.

Many boaters find that structured RYA courses help unlock the full potential of their radio, from crisp routine calls to the calm delivery of a distress message. Instructors emphasize clear communication, patience, and practical scenarios, making training approachable for everyone—beginners and seasoned sailors alike. Real-world experience, whether on a day course or a longer voyage, ensures you’re ready for any situation, from requesting a fuel stop to hailing the Coastguard during an emergency.

A VHF marine radio isn’t just a box of buttons—it’s your on-board safety net and a key part of the adventure afloat.

The Maritime Mobile Band and VHF Channel Allocation

To keep communication on the water clear and organized, VHF marine radios use a specific range of radio frequencies called the Maritime Mobile Band. This band is overseen globally by the International Telecommunications Union (ITU), which makes sure that vessels everywhere can talk to each other, no matter their flag or location.

Within this band, individual frequencies are grouped into channels. Originally, there were just 28 channels, but as more mariners took to the airwaves, congestion became an issue. Rather than disrupt existing maritime and land-based services, more channels were squeezed in between the original ones—expanding the total up to 55 main channels. You’ll notice, however, that channel numbers jump from 28 to 60; that’s because channels 29 to 59 are used by other communications services, not by maritime radios.

Most modern VHF radios offer over 56 channels, but not all are for general use—some are marked as “private” or “special purpose” channels, and aren’t part of the internationally recognized Maritime Mobile Band. For safe boating, it’s best to be familiar with the standard channels for calling, emergencies, and navigation. These ensure that whether you’re contacting the Coastguard or chatting with the marina, your radio transmission will reach the right ears.

Types of VHF Marine Radio Calls

Routine Calls

Routine calls on a VHF marine radio handle “ship-related business,” like coordinating meetups or requesting fuel stops. Avoid non-essential chatter.

• Channels: Use 6, 8, 72, or 77 at low power to minimize range.
• Non-DSC Calls: Start on Channel 16, then switch to a working channel after confirming it’s clear (listen for 2 minutes).
• DSC Calls: Select the working channel during setup, requiring the recipient’s MMSI, bypassing Channel 16.
• Note: Coastguard or port authorities may dictate the working channel. Large ships use Channel 13 for bridge-to-bridge.

Safety Calls – “SECURITAY”

Pronounced “SAY-CURE-IT-TAY,” safety calls via VHF marine radio broadcast navigational or weather warnings to “all ships” or “all stations,” often by the Coastguard. Examples include debris hazards or wind alerts. Anyone can issue a safety call if needed.

Urgency Calls – “PANPAN”

“PAN-PAN” calls on a VHF marine radio address non-life-threatening issues, like breakdowns or medical advice requests.

• Addressed to: Usually “all stations” (vessels, land stations, aircraft).
• Example: Requesting a tow or medical guidance.

Distress Calls – “MAYDAY”

A “MAYDAY” call on a VHF marine radio signals imminent danger, sent via DSC and voice. Use the MIPDANIO acronym:

• Mayday
• Identify (name, call sign, MMSI)
• Position
• Distress type
• Assistance needed
• Number of people
• Information (e.g., lifejackets)
• Over

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 Over

Urgency Call Example

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

Mayday Relay

A Mayday Relay via VHF marine radio reports a distress situation for another vessel or person.

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 Position 51°44’.71N 001°04’.32E They Require Immediate Assistance They Are Wearing a Life Jacket We Are Proceeding Towards Them Over

Radio Procedure

When using a VHF marine radio, split position numbers for clarity: e.g., 51°44’.71N becomes “Fife one degrees, four four minutes, decimal seven one north.”

UK VHF Marine Radio Channels

The UK uses the “International Frequency” system for VHF marine radio, with ~57 channels plus private ones. Channel 16 (156.800MHz) is the global distress and calling channel. Check local regulations outside UK waters.

Channel	Purpose	Notes
16	Distress, Safety, Calling	Keep calls brief (<1 min); switch to working channels.
70	DSC	Digital-only; no voice.
13	Bridge-to-Bridge	For collision avoidance.
6, 8, 72, 77	Inter-Ship	For routine communication.
11, 12, 14	Port Operations	Check Admiralty List.
15, 17, 75, 76	Guard Channels	Low-power (1W).
67	UK Small Craft Safety	HM Coastguard; use after Channel 16 in Solent.
65	National Coastwatch	For radio checks, weather.
80	Marina Communications	Duplex; listen 1 min.
M1/M2	Private (e.g., race control)	UK-only; licensed.

Simplex vs. Duplex: Simplex uses one frequency; duplex uses separate frequencies, limiting ship-to-ship use (e.g., Channel 80).

Private Channels: Channels 29–59, 00, 0 require licensing. Unauthorized use risks Ofcom fines.

Why Are There Gaps in VHF Channel Numbers?

If you’ve ever glanced through the VHF marine radio channel list and wondered, “Hang on, what happened to channels 29 through 59?”, you’re not alone. The missing numbers aren’t the result of a clerical error or a maritime in-joke.

In the early days, VHF maritime radio originally had 28 channels. As radio use surged, congestion became a real headache—think London Tube at rush hour, but for radio waves. Since no additional frequencies were available, radio authorities needed to squeeze more channels into the same radio spectrum. They did this by “interleaving” new channels between the original ones, boosting the total available maritime channels to 55.

But here’s the catch: numbers 29 to 59 were already earmarked for other services (notably commercial and land-based operations). To avoid confusion, newly created marine channels were instead numbered 60 to 88, skipping over the whole 29–59 range. That’s why the VHF marine channel list has its own curious “missing middle”—a bit of radio history hiding in plain sight.

Why Duplex Radios Are Found on Large Vessels and Shore Stations

Duplex channels work a bit like a classic phone call: one frequency for speaking, another for listening—allowing simultaneous two-way radio traffic. While this sounds convenient, there’s a practical hitch for the average boater.

To use a duplex radio, you’re required to fit two separate aerials—one for transmitting, the other for receiving. These aren’t just for show; they have to be spaced far enough apart so that your outgoing signal doesn’t overwhelm your own receiver. That’s a tall order on a compact yacht or RIB, but much more feasible on a large ship or at a shore stations, where there’s room for proper installation. If the aerials are too close, you risk feedback and potentially damaging your radio equipment.

Because of these technical demands, duplex radios live mainly on big vessels and land-based stations—where there’s space and infrastructure to match. For small craft, simplex channels (using just one frequency at a time) are the go-to option.

Limitations of Monitoring Duplex Channels with Semi-Duplex Radios

It’s worth noting that semi-duplex (or “simplex only”) radios have their quirks when it comes to listening in on duplex channels. Here’s where things get tricky:

• No Ship-to-Ship Chat: Duplex channels are built for ship-to-shore communications—your set transmits on one frequency and receives on another. Boats can’t talk directly to each other over duplex, even if both are tuned in.
• Partial Conversations: If you’re using a semi-duplex radio to tune in, you’ll only catch half the exchange—the shore station. The ship’s side of the chat is broadcast on a different frequency you can’t receive, leaving you with a lopsided conversation and possibly more confusion than clarity.
• Missed Messages: Trying to monitor a full ship-to-shore discussion over a duplex channel with only simplex capabilities means important details from the ship’s end will be missing. In critical moments, this could mean missing instructions, warnings, or urgent updates.

So, while it might seem like you’re listening in, you’re really only getting the shoreline of the story. For complete coverage, a proper duplex-capable radio is essential.

Understanding Semi-Duplex Operation

Semi-duplex operation is a feature found on most VHF marine radios, allowing communication on duplex channels despite only having a single antenna. In this setup, your radio can transmit on one frequency and receive on another, but not at the same time—when you press the transmit button, you’re sending, and releasing it switches back to receiving.

Because you can’t hear and talk at once (unlike a true landline call), you’ll still need to say “over” so the other party knows it’s their turn. Even though the radio handles the switching automatically, the user experience is much like a normal (simplex) channel—one speaks while the other listens.

A key point: duplex channels are intended strictly for ship-to-shore calls. If you try to contact another vessel on a duplex channel, it won’t work—your radios will be sending and receiving on opposite frequencies and never connect. Similarly, if you listen in on a duplex conversation, you’ll only catch the shore side, not the ship’s reply.

VHF Marine Radio Types: Handheld vs. Fixed

Handheld VHF Marine Radios

Handheld VHF marine radios are portable and ideal for emergencies or close-range tasks.

Pros	Cons
Portable; fits in pocket	Limited battery life
Independent battery	Shorter range
Easy to use	Lower power (1–6W)
No installation	Less clear audio

Fixed Mounted VHF Marine Radios

Fixed VHF marine radios offer greater range and power for offshore use.

Pros	Cons
Unlimited power	Fixed installation
Longer range	Relies on vessel’s power
DSC/GPS integration	Requires shore repairs
Clearer audio	No privacy

Why Both? Combining fixed and handheld VHF marine radios ensures redundancy. Learn more about essential boating gear.

VHF Marine Radio Performance

VHF marine radio range depends on antenna height: Range (nm) = 2.5 × √(antenna height in meters). Handhelds reach ~10 nm; fixed units reach ~60 nm.

VHF Marine Radio Licensing

Ships Radio Licence

Authorizes VHF marine radio and other equipment on UK-registered vessels.

Ships Portable Radio Licence

Permits handheld VHF marine radios across multiple vessels, ideal for kayakers.

Pro Words for VHF Marine Radio

Pro Word	Meaning
Acknowledge	Confirm receipt
Affirmative	Yes
Break Break	Urgent interruption
Correction	Error; retransmit
I say again	Repeating message
I spell	Spelling with phonetic alphabet
Negative	No
Out	End; no reply
Over	End; reply expected
Radio check	Test signal
Relay to	Transmit to addressee
Roger	Received
Say again	Repeat
Station Calling	Identify caller
This is	Caller’s ID
Wait	Brief pause
Sécurité	Safety alert
Pan Pan	Urgency call
Mayday	Distress call

Phonetic Alphabet

Letter	Pronunciation	Letter	Pronunciation
A	ALPHA	B	BRAVO
C	CHARLIE	D	DELTA
E	ECHO	F	FOXTROT
G	GOLF	H	HOTEL
I	INDIA	J	JULIET
K	KILO	L	LIMA
M	MIKE	N	NOVEMBER
O	OSCAR	P	PAPPA
Q	QUEBEC	R	ROMEO
S	SIERRA	T	TANGO
U	UNIFORM	V	VICTOR
W	WHISKY	X	X-RAY
Y	YANKEE	Z	ZULU
1	WUN	2	TOO
3	TREE	4	FO-WAR
5	FIFE	6	SIX
7	SEVEN	8	ATE
9	NINER	0	ZERO

VHF Marine Radio Knowledge Test

Complete this test for your RYA VHF/SRC course.

Q1: Handheld VHF Marine Radio Licence

What licence is needed for a handheld VHF marine radio as a UK dinghy instructor?

Answer: Ships Portable Radio Licence for use across vessels in UK waters.

Q2: Race Officer Channel Selection

Which channel for race communications at Royal Commodore Yacht Club, and why?

Answer: Use Channel M1/M2 for race control, avoiding interference with distress channels.

Q3: Responding to Unknown Caller

What pro word for an unknown caller on a VHF marine radio?

Station Calling, Station Calling, Station Calling This is [Your Vessel Name], [Your Vessel Name], [Your Vessel Name] Call Sign [Your Call Sign], MMSI [Your MMSI] Please Identify Yourself Over

Q4: Urgency Call for Broken Arm

Fishing boat “Breaking Bass” at 50°49’.85N 001°20’.75W, crew member with broken arm. What call and channel?

Pan-Pan, Pan-Pan, Pan-Pan All Stations, All Stations, All Stations This is Fishing Boat Breaking Bass, Breaking Bass, Breaking Bass Call Sign M3TH5, MMSI 235897546 My Position Fife Zero Degrees Four Niner Minutes Decimal Eight Five North, Zero Zero Wun Degrees Two Zero Minutes Decimal Seven Five West Crew Member Has Broken Arm, Request Medical Advice Five Persons on Board, Lifejackets and Liferaft Available Over

Q5: Distress Call for Grounding

Sailing vessel “Ship Happens” grounded at 49°27’.85N 004°08’.89W. What DSC alert and voice message?

Mayday, Mayday, Mayday This is Sailing Vessel Ship Happens, Ship Happens, Ship Happens Call Sign W4T3R, MMSI 232461276 Mayday Ship Happens, Call Sign W4T3R, MMSI 232461276 In Position Four Niner Degrees Two Seven Minutes Decimal Eight Five North, Zero Zero Four Degrees Zero Eight Minutes Decimal Eight Niner West Grounded on Lookout Sands, Taking on Water, Keel Cracking I Require Immediate Assistance Four Persons on Board, No Lifejackets, Liferaft Available Over

Q6: Safety Call for Floating Debris

Motor vessel “Water U Looking At” spots tree stumps at 50°59’.10N 001°34’.88W. What DSC alert and voice message?

Sécurité, Sécurité, Sécurité All Stations, All Stations, All Stations This is Motor Vessel Water U Looking At, Water U Looking At, Water U Looking At Call Sign 6UNH0, MMSI 234754297 In Position Fife Zero Degrees Five Niner Minutes Decimal One Zero North, Zero Zero Wun Degrees Three Four Minutes Decimal Eight Eight West Floating Tree Stumps, 30 Meters Wide, 45 Meters Long, Drifting South Easterly, Navigation Hazard Over

Q7: Urgency Call for Prop Foul

Motorboat “Knot 2 Bad” with a fouled prop at 49°59’.85N 001°23’.23E. What DSC alert and voice message?

Pan-Pan, Pan-Pan, Pan-Pan All Stations, All Stations, All Stations This is Motorboat Knot 2 Bad, Knot 2 Bad, Knot 2 Bad Call Sign Zero India Wun Delta Zero, MMSI 235879541 My Position Four Niner Degrees Five Niner Minutes Decimal Eight Five North, Zero Zero Wun Degrees Two Three Minutes Decimal Two Three East Line Wrapped Around Propeller, Request Assistance for Tow Four Persons on Board Over

Q8: Distress Call for Medical Emergency

Fishing trawler “Master Baiter 2” with a skipper heart attack at 48°51’.84N 000°20’.01W. What DSC alert and voice message?

Mayday, Mayday, Mayday This is Fishing Trawler Master Baiter 2, Master Baiter 2, Master Baiter 2 Call Sign Wun Delta India Three Tango, MMSI 235798465 Mayday Master Baiter 2, Call Sign Wun Delta India Three Tango, MMSI 235798465 In Position Four Eight Degrees Five Wun Minutes Decimal Eight Four North, Zero Zero Zero Degrees Two Zero Minutes Decimal Zero Wun West Skipper Suffered Heart Attack, Medical Emergency I Require Immediate Assistance Six Persons on Board, Lifejackets, Liferaft, and Flares Available Over

Q9: Safety Call for Abandoned Kayak

Sailing vessel “No Worries” finds an abandoned kayak at 50°13’.26N 001°39’.89W. What voice message and channel?

Sécurité, Sécurité, Sécurité All Stations, All Stations, All Stations This is Sailing Vessel No Worries, No Worries, No Worries Call Sign Charlie Four Wun Lima Five, MMSI 235130875 In Position Fife Zero Degrees One Three Minutes Decimal Two Six North, Zero Zero Wun Degrees Three Niner Minutes Decimal Eight Niner West Found Abandoned Kayak Named Sotally Tober with Gear, Including Wallet and Recent Food, at 1454 Possible Missing Person, Request Coastguard Assistance Over

Conclusion

Mastering VHF marine radio is vital for safe boating. Review the RYA VHF/SRC course for hands-on training.

Key Points:

• Call Types: Routine, Safety, Urgency, Distress.
• Channels: Channel 16 for distress; UK-specific channels like 67, 80.
• Equipment: Fixed and handheld VHF marine radios for redundancy.
• Licensing: Ships Radio or Portable Radio Licence.
• Preparation: Use procedure cards and practice phonetic alphabet.

Next courses and steps?

Learn more about RYA raining courses https://commodore-yachting.com/sailing-courses/) to master its use. Whether you’re interested in sailing, powerboating, or even expanding your skills to activities like stand-up paddleboarding or windsurfing, there are courses and qualifications suitable for every level and age group. From family-friendly sessions for beginners (ages eight and up) to advanced cruising and yachting programs, structured training ensures you’re prepared for safe, confident boating—no matter your vessel or ambition.