Maritime Phonetic Alphabet on Marine VHF

Which alphabet maritime radio uses

Marine VHF radio uses the same code words as the rest of international radiotelephony — Alfa, Bravo, Charlie through Zulu — drawn from the ICAO/ITU radiotelephony spelling alphabet. The full table, with pronunciations, is on the home page. Maritime services adopted the alphabet through the ITU Radio Regulations rather than through ICAO directly, but the words are identical.

That uniformity matters: a French sailor working with a Dutch coast station and a Norwegian cargo vessel all rely on the same code words. The same is true of the digit pronunciations — "wun, too, tree, fower, fife, six, seven, ait, niner" — although in light maritime traffic many recreational operators speak the digits as plain English numbers and only switch to spelled forms when readability suffers.

When the phonetic alphabet is actually needed

Most routine marine VHF traffic is short and human-friendly — a quick call to a marina, a passing report to a lock keeper, a friendly hail between two yachts. The phonetic alphabet only appears when the message can be confused over the air:

• Vessel name on first contact. Particularly with a long, foreign, or unusual name. "Sailing yacht Mistral, Mike–India–Sierra–Tango–Romeo–Alfa–Lima."
• Call sign and MMSI. Pleasure-craft call signs are issued letter-and-number combinations; reading them digit-by-digit is essential. MMSI numbers are always read digit-by-digit.
• Position when given as a grid or chart reference. Lat/long is normally read in plain digits, but cross-checking a single doubtful character is faster phonetically.
• Channel changes. "Confirm switching one-six to seven-two" — the digit-pair format is universal.
• Distress, urgency, and safety messages. Where ambiguity has consequences. The MAYDAY structure prescribes spelled vessel name and a position read with care.

Hailing procedure on Channel 16

Channel 16 (156.800 MHz) is the international hailing and distress channel. Pleasure-craft and commercial traffic alike use it to make initial contact, then move to a working channel. The standard hailing format is short and predictable:

• Three-by-three call. Call the station up to three times, identify yourself up to three times, finish with "over." Example: "Saint Catherines Marina, Saint Catherines Marina, Saint Catherines Marina, this is sailing yacht Mistral, Mistral, Mistral, over."
• Phonetic spelling on first contact. If the vessel name is in any way ambiguous, spell it once after the third repetition: "…this is sailing yacht Mistral — Mike–India–Sierra–Tango–Romeo–Alfa–Lima — over."
• Switch to a working channel. The hailed station typically replies and proposes a working channel: "Mistral, this is Saint Catherines Marina, switch and answer channel seven-two." The originator confirms: "Switching seven-two."
• Keep Channel 16 clear. Once contact is established, conversation moves immediately. Channel 16 is not a chat channel.

In some regions Channel 9 is the recreational hailing channel and Channel 16 is reserved more strictly for distress. Local rules take precedence; the spelling procedure is the same on either.

MAYDAY: distress procedure

A distress call uses the prefix MAYDAY, spoken three times, and a fixed structure. Phonetic spelling appears in the vessel-name field and, if needed, when reading back position elements that the receiving station did not catch.

1. Distress signal. "MAYDAY, MAYDAY, MAYDAY."
2. Identify the vessel three times. "This is sailing yacht Mistral, Mistral, Mistral."
3. Spell on third repetition if name is foreign or unusual. "Mike–India–Sierra–Tango–Romeo–Alfa–Lima."
4. Repeat the distress call once more, with call sign or MMSI. Digits read individually: "two-three-two-zero-zero-niner-eight-seven-six."
5. Position. Latitude and longitude in degrees and decimal minutes, or a bearing-and-range from a recognized landmark.
6. Nature of distress. Sinking, fire, person overboard, medical, etc.
7. Assistance required.
8. Number of persons on board.
9. Other useful information. Vessel description, lifesaving equipment carried.
10. "Over."

If you receive a MAYDAY, do not transmit unless you can render assistance or unless several minutes pass with no response from a coast station. Listen, log the time, and be ready to relay.

PAN-PAN and SÉCURITÉ

The same prefix-three-times structure governs the two lower-priority safety calls.

• PAN-PAN (pronounced "pahn-pahn"), repeated three times, indicates urgency without immediate threat to life — for example, a disabled vessel adrift in shipping lanes. Phonetic spelling is used in the same fields as a MAYDAY.
• SÉCURITÉ (pronounced "say-cure-it-tay"), repeated three times, prefixes safety information broadcast to all stations — typically navigational warnings or weather advisories from a coast radio station. Recreational operators rarely originate a SÉCURITÉ; they listen for them.

DSC and where the phonetic alphabet still matters

Modern marine VHF sets include Digital Selective Calling (DSC). A DSC distress alert sends the vessel's MMSI, position from a connected GPS, and the nature of distress as data. The radio then opens the voice channel for follow-up. Phonetic spelling still matters for the voice portion: the first thing a coast station typically asks for is a confirmation of the vessel name and any details DSC didn't carry.

Treat DSC as the headline; the voice that follows is the article. Practice the voice procedure even if your set has a red distress button. A clean spelled callout reaches a wider audience — vessels nearby will hear it too, and may be closer than the coast station.

Call signs, MMSI, and license letter prefixes

Marine call signs are usually a combination of one or two prefix letters (assigned by the licensing country) and a string of letters and digits. They are read entirely phonetically, alternating spelled letters and spelled digits as the string requires. A few practical points:

• Always spell the prefix letters. "Golf-Bravo" not "GB" — the latter sounds like static.
• Read MMSI as digits. Nine digits, individual: "two-three-two — zero-zero-niner — eight-seven-six." Group spacing helps the listener write them down without re-asking.
• Don't invent shortcuts. Recreational sailors sometimes drop the prefix letters once contact is made. On a noisy frequency, reverting to the full phonetic call sign on the first transmission of each new exchange prevents confusion.

Spelling a position

Lat/long is normally read as plain digits, with units called out: "Position five-zero degrees one-two decimal four north, zero-zero-five degrees three-eight decimal niner west." Phonetic spelling enters the procedure in three situations:

1. The receiving station asks for a repeat of a single doubtful digit. Read the surrounding digits and the doubtful one phonetically: "…one-two — that is one-too — decimal four…"
2. The position is given as a place name with a bearing and range. The place name is spelled if it isn't obviously English or local: "Bearing one-eight-zero from Roches Douvres — Romeo–Oscar–Charlie–Hotel–Echo–Sierra — distance four miles."
3. A sea area or chart reference is used (e.g. UK Met Office shipping forecast areas). Names like "Fastnet" or "Lundy" are normally spoken plainly; obscure references should be spelled.

Common mistakes

• Improvising phonetics. "B as in Boat" works for a brief casual hail but breaks down on a noisy distress frequency where the listener may not share your first language. Use the standard ICAO words. The full reasoning is on our pronunciation guide.
• Spelling everything. A long routine message read entirely phonetically is harder to follow than the same message in plain language. Spell the vessel name and any ambiguous element; leave the rest plain.
• Forgetting "over" and "out." "Over" invites a reply; "out" closes the exchange. They are not interchangeable, and saying "over and out" together is a common landlubber error.
• Reading digits as numbers. "Channel seventy-two" is acceptable in friendly traffic but on a busy frequency "channel seven-two" is unambiguous. The same applies to MMSI and call-sign digits.
• Treating Channel 16 as a chat channel. Once contact is made, switch immediately. Long conversations on 16 cover other vessels' attempts to call distress.

A practical readiness checklist

If you've fitted a marine VHF and want to be confident before you cast off:

• Run through the alphabet from memory using our text-to-phonetic converter with your vessel name as the input.
• Drill the digit pronunciations — "wun, too, tree, fower, fife, six, seven, ait, niner" — until they're reflexive.
• Write a MAYDAY card and laminate it: vessel name, call sign, MMSI, the standard nine-line distress format. Stick it next to the radio.
• Practice with a buddy on a working channel. Read each other's vessel names, MMSIs, and positions; correct the readbacks.
• Remember the priority order: MAYDAY beats PAN-PAN beats SÉCURITÉ beats routine traffic. If you hear any of them, stop transmitting and listen.