What is Channel 16, and why is it so important?

Channel 16 (156.800 MHz) is the international frequency for distress calls, safety messages, and hailing other vessels. It's monitored 24/7 by Maritime Radio and is your lifeline in an emergency. Using it for a casual chat is the marine equivalent of calling 111 to order a pizza, it clogs up a channel that genuinely needs to stay clear.

Can I chat with friends on another boat over VHF?

Yes, but not on Channel 16. For casual ship-to-ship chat, use the designated inter-ship or non-commercial channels, in New Zealand these are channels 06, 08, 72 and 77. Keep it short: the airwaves are a shared resource, and brief conversations keep the channel clear for safety messages or operational calls.

How do I correctly do a radio check before heading out?

Never do a radio check on Channel 16, that channel must stay clear for genuine distress calls. Switch to a designated ship-to-ship or local Coastguard working channel instead, channels 63, 64 or 65 are commonly used for this, then carry out your check there.

What's the difference between Mayday, Pan Pan and Sécurité calls?

Mayday is for grave and imminent danger, fire, sinking, a life-threatening medical situation, and gets an immediate response from anyone listening. Pan Pan is for serious but not immediately life-threatening situations, like a lost propeller or non-critical engine failure. Sécurité is for safety announcements about navigational hazards or weather warnings, such as a submerged shipping container or an incoming storm.

What's a simplex channel versus a duplex channel?

A simplex channel works like a normal two-way radio, only one person can talk at a time. A duplex channel is more like a phone call, using two frequencies at once so both people can talk and listen simultaneously. Most everyday boat-to-boat chat happens on simplex; duplex is typically reserved for calls to a marina or Maritime Radio.

What two things do I legally need to operate a marine VHF radio?

A Maritime Ship Radio Licence for your vessel, which registers the radio equipment and assigns a unique callsign, and a Maritime VHF Radio Operator Certificate (MVROC) for the person actually using the radio, proving you know the correct procedures. Operating without either is illegal and can result in significant fines.

Can I use a marine VHF radio from land?

No, not without specific authorisation from Radio Spectrum Management. Marine VHF frequencies are strictly reserved for vessels at sea, and using them from shore can interfere with genuine search and rescue operations. If you need land-based communication, a dedicated UHF PRS radio or a commercial land mobile frequency is the correct tool instead.

What is an MMSI number, and why does it matter?

An MMSI (Maritime Mobile Service Identity) is a unique nine-digit number programmed into your DSC-equipped radio, essentially your vessel's digital fingerprint. It's issued automatically when you apply for your Ship's Radio Licence, and it's what powers the one-touch DSC distress button, sending your identity and location instantly without a word being spoken.

Is the Maritime Ship Radio Licence a one-off, or does it need renewing?

It's a lifetime licence for that vessel. Once issued, your callsign and MMSI stay with the boat, there's no annual renewal requirement to maintain it.

What actually happens when I press the DSC distress button?

Your radio sends a rapid digital alert on Channel 70, instantly transmitting your vessel's MMSI, your precise GPS coordinates (if your radio is connected to GPS), and the nature of your distress. Every DSC-equipped radio within range sounds an alarm, this bypasses the need for voice communication entirely during the critical first seconds of an emergency, which matters if the crew is injured or unable to speak.

What should I do if I accidentally trigger a DSC distress alert?

Immediately broadcast a cancellation message: clearly state your vessel name and callsign, then announce that the alert was accidental and there's no emergency. Don't simply turn the radio off, that leads rescue authorities to believe a genuine disaster has occurred and can trigger unnecessary helicopter or lifeboat deployment.

What's AIS, and is it worth having alongside DSC?

AIS (Automatic Identification System) lets your radio "see" other AIS-equipped vessels, displaying their name, speed and heading directly on your radio or chartplotter. It's particularly useful in busy waters like the Waitemata Harbour or the approaches to the Port of Tauranga, helping you identify large commercial ships and even call them directly by name via DSC rather than making a vague general call.

What's dual-watch or tri-watch, and why would I use it?

It lets your radio monitor Channel 16 (the primary distress and hailing channel) while simultaneously listening to one or two other channels, like your local Coastguard working channel. This means you won't miss a critical safety call while you're communicating on a different channel.

What range can I realistically expect from a marine VHF radio?

VHF is line-of-sight, so antenna height is the single biggest factor. For a typical small boat talking to another small boat, expect roughly 5 to 10 nautical miles (around 9 to 18km). Higher-mounted antennas on larger vessels or shore stations can reach considerably further.

Is a handheld VHF radio enough for offshore sailing?

No, a handheld shouldn't be your primary offshore communication tool. Handheld units are limited to 5 or 6 watts of power, restricting range to roughly 5 to 8km in most sea conditions. A fixed-mount unit with a properly installed external antenna is the appropriate primary system; a handheld makes an excellent backup.

Why does antenna and installation quality matter as much as the radio itself?

Your radio system is only as good as its weakest link. A top-of-the-line radio will perform poorly if connected to a low-quality antenna or installed with corroded wiring. Investing in a proper installation is just as important as the radio purchase itself.

What does the Maritime NZ shore network actually cover?

28 coastal stations cover the mainland, with two more covering the Chatham Islands, all monitoring Channel 16 around the clock. Be aware that signal blind spots can still occur near steep cliffs or deep inside fiords, so don't assume coverage is perfect everywhere.

Can you supply and install a marine VHF radio correctly configured for my vessel?

Yes. We provide nationwide delivery and professional installation, ensuring your radio is correctly configured with your MMSI number for full DSC functionality from day one, not left as something you have to sort out yourself after fitting it.