VHF Channel Quick Reference
The OUPV exam tests knowledge of these key channels.
| Channel | Primary Use | Type |
|---|---|---|
| 16 | Distress, safety, and calling (mandatory watch) | Required |
| 6 | Inter-ship safety communications | Safety |
| 9 | Recreational calling channel (alternative to 16) | Calling |
| 12 | Port operations and vessel traffic | Port Ops |
| 13 | Bridge-to-bridge navigation (1 watt) | Navigation |
| 14 | Port operations and vessel traffic | Port Ops |
| 22A | U.S. Coast Guard working channel | USCG |
| 25–28 | Public correspondence (ship-to-shore) | Phone |
| 67 | U.S. inland waters bridge-to-bridge | Navigation |
| 70 | Digital Selective Calling (DSC) only — no voice | DSC |
| WX1–WX3 | NOAA weather broadcasts (receive only) | Weather |
Standard Calling Procedure
Initiate contact on Ch 16 (or Ch 9 recreational), then switch to a working channel.
Call on Ch 16
"[Vessel name] × 3, THIS IS [your vessel name] × 3, OVER"
Wait for response
If no response in 2 minutes, try again. After 3 attempts, wait 15 minutes.
Agree on working channel
"Switch to channel [XX], OVER"
Confirm and switch
"Roger, switching [XX]" — both vessels move to working channel
Conduct business
Keep transmissions brief. End each with OVER (awaiting reply) or OUT (conversation complete).
Return to Ch 16
After completing your communication, return to Channel 16 watch.
MAYDAY Distress Call
Use MAYDAY only for grave and imminent danger to life or vessel. Transmit on Channel 16.
PAN PAN (Urgency)
Use when safety is at risk but not immediately life-threatening. Same format, replace MAYDAY with PAN PAN × 3.
SECURITE (Safety)
Navigational hazard warnings. Broadcast by Coast Guard. "SECURITE SECURITE SECURITE, ALL STATIONS..."
Digital Selective Calling (DSC)
DSC is a digital distress system built into Class D VHF radios. Channel 70 is used exclusively for DSC — no voice transmissions.
MMSI Number
9-digit Maritime Mobile Service Identity. Register your vessel's MMSI with BoatUS, Sea Tow, or FCC. Free through BoatUS/Sea Tow for recreational vessels.
DSC Distress Alert
Press and hold the DSC distress button for 5 seconds. Radio transmits your MMSI, position (if GPS-linked), and nature of distress on Ch 70. Then switch to Ch 16 for voice communication.
DSC Key Facts for Exam
Channel 70 = DSC only (no voice)
MMSI must be registered before use
GPS link allows automatic position broadcast
DSC alerting ≠ voice distress — must follow with voice on Ch 16
DSC radios are Class D — minimum required for offshore
All vessels ≥ 20m must have DSC (internationally)
Radio Terminology
| Term | Meaning |
|---|---|
| OVER | Transmission complete — reply expected |
| OUT | Transmission complete — conversation finished (no reply expected) |
| ROGER | Message received and understood |
| WILCO | Will comply with instructions received |
| AFFIRMATIVE | Yes (do not say 'yeah' or 'yes') |
| NEGATIVE | No |
| SAY AGAIN | Repeat your last transmission (never say 'repeat' — it means artillery fire in military) |
| STAND BY | Wait; I will call you shortly |
| BREAK | Interruption between sections of a long message |
| SEELONCE MAYDAY | Silence MAYDAY — silence all other traffic (issued by rescue authority) |
NATO Phonetic Alphabet
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
Papa
Q
Quebec
R
Romeo
S
Sierra
T
Tango
U
Uniform
V
Victor
W
Whiskey
X
X-ray
Y
Yankee
Z
Zulu
FCC Licensing
Ship Station License
Required if traveling to foreign ports, using SSB/HF radio, or operating a commercial vessel. 10-year term, filed online with FCC.
Restricted Radiotelephone Operator Permit
Required for captains and anyone who operates a ship station radio. One-time fee, no exam required. File FCC Form 605.
Recreational Exemption
U.S. recreational vessels in U.S. waters are exempt from ship station licensing. But if you carry passengers for hire, you are NOT recreational.
Exam Strategy
Memorize Channel 16 and 22A
Ch 16 = distress/calling (always monitor). Ch 22A = USCG working channel. These appear on virtually every exam.
Channel 70 = DSC only
No voice transmissions on Ch 70. Exam questions often ask what happens on Ch 70 — the answer is digital DSC alerting only.
Know the 3 urgency levels
MAYDAY (grave/imminent danger) > PAN PAN (urgency) > SECURITE (safety/nav hazard). Order matters on the exam.
Bridge-to-bridge = Ch 13
Navigation communication between vessels uses Ch 13 at 1 watt. Inland waters use Ch 67 in some areas.
Frequently Asked Questions
What channel should I monitor when underway?
Channel 16 is the international distress, safety, and calling channel. All vessels equipped with VHF radio are required to monitor Channel 16 whenever the radio is on, except when actually communicating on a working channel.
What is the MAYDAY procedure?
Transmit on Channel 16: (1) MAYDAY MAYDAY MAYDAY, (2) THIS IS [vessel name × 3], (3) MAYDAY [vessel name], (4) position or location, (5) nature of distress, (6) number of persons on board, (7) any other useful information, (8) OVER. Wait for response. If no response, repeat on Channel 16 and try 2182 kHz (MF).
Do I need an FCC license to operate a marine VHF radio?
In U.S. waters only, recreational vessels are generally exempt from FCC ship station licensing. However, if you travel to foreign ports, use SSB (MF/HF) radio, or operate a commercial vessel, you need an FCC Ship Station License. As a licensed captain, you also need a Restricted Radiotelephone Operator Permit (RR) to legally operate the radio.
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