How to Use a VHF Marine Radio: Channels, Mayday Calls, and Etiquette
A VHF marine radio is one of the most essential pieces of safety equipment on any vessel, whether you’re heading out for a casual harbour cruise or embarking on a full sailing adventure in Sydney. Unlike mobile phones, VHF radios provide reliable, real-time communication on the water—connecting you with nearby boats, marine rescue services, and harbour authorities. Knowing how to use one correctly ensures you can call for help, communicate clearly, and navigate Australia’s waterways with confidence.
This guide walks you through the fundamentals: understanding channels, making a proper Mayday call, and following essential radio etiquette.
Why VHF Marine Radios Matter
VHF radios operate on dedicated marine frequencies that are monitored 24/7 by maritime authorities. They’re faster, clearer, and far more reliable than mobile reception, especially once you venture offshore or into remote areas. They also allow communication with all nearby vessels at once—crucial during emergencies. Whether you’re a seasoned skipper or a weekend boatie, every person at the helm should be familiar with the basics of VHF communication.
Key VHF Channels You Need to Know
Marine radios operate on a range of channels, each with a specific purpose. Understanding these ensures your communication is sent to the right place and prevents misuse of emergency frequencies.
Channel 16 – Distress, Urgency & Calling
This is the most important channel. It’s monitored by Marine Rescue, the coastguard, and commercial vessels. Use Channel 16 for:
Mayday calls
Urgency or safety calls
Initial contact with another vessel before switching to a working channel
Keep radio chatter here to a minimum unless necessary.
Channel 67 – Australian Safety Channel
Used for safety information and additional monitoring. It serves as a backup to Channel 16 and is ideal for non-emergency safety communications.
Working Channels (72, 73, 77)
These are commonly used for boat-to-boat communication once initial contact is made on Channel 16.
Weather Channels
Most marine radios include dedicated weather channels broadcasting Bureau of Meteorology updates and warnings. Check your radio’s manual for your local frequency.
How to Make a Proper Mayday Call
In an emergency where there's immediate danger to life, you must send a Mayday call. Clarity and structure are key.
Follow this format:
Say “Mayday, Mayday, Mayday.”
State your vessel name and call sign three times.
Provide your position.
Use GPS coordinates, bearing and distance from a landmark, or location description.
Describe the emergency.
Example: “Taking on water,” “Engine room fire,” or “Man overboard.”
State the assistance required.
Provide details about people on board.
Describe your vessel (size, colour, type).
Over.
Example: “Mayday, Mayday, Mayday. This is Blue Horizon, Blue Horizon, Blue Horizon. Our position is two nautical miles east of South Head. We are taking on water and cannot control the flooding. Four people on board. Require immediate assistance. Over.”
Speak slowly, clearly, and naturally—panic only creates confusion.
When to Use ‘Pan-Pan’ Instead of Mayday
Pan-Pan is used for urgent situations that are serious but not immediately life-threatening, such as:
Engine failure in busy shipping channels
Medical concerns that require attention but aren’t critical
Loss of steering with no immediate danger
The structure is similar to a Mayday call but begins with “Pan-Pan, Pan-Pan, Pan-Pan.”
Essential VHF Radio Etiquette
Marine radios are for safety and navigation—not casual chatting. Good etiquette ensures channels stay clear for those who need them.
Keep messages brief and relevant: Use clear, concise language. Overly long transmissions clog channels.
Identify yourself properly: Before speaking, state your vessel name: “Blue Horizon to Sea Mist, over.”
Use “over” and “out” correctly
Over means you expect a reply.
Out means the conversation is finished. Never say “over and out”—they contradict each other.
Don’t interrupt emergency traffic: If someone calls “Mayday” or “Pan-Pan,” stop transmitting immediately unless you can assist.
Monitor Channel 16 while underway: Even if you’re chatting on another channel, always return to or dual-watch Channel 16 for safety alerts.
Check volume and squelch settings: Poor quality audio can make vital messages unclear. Adjust your settings before leaving the marina.
Tips for First-Time VHF Users
Practise before you need it – Make test calls responsibly on working channels.
Log on with Marine Rescue NSW when heading out and log off when you return.
Secure your radio so it can’t fall overboard—float-free or handheld waterproof units are ideal as backups.
Carry a handheld VHF radio in case of power loss aboard.
A VHF marine radio is more than just a communication tool—it’s an essential safety lifeline for every boatie
Understanding channels, using correct emergency formats, and following good etiquette ensures you’re prepared for both everyday interactions and unforeseen emergencies on the water. Whether you’re planning a relaxed day trip or an unforgettable sailing adventure, mastering your marine radio means navigating with confidence and capability.
