A VHF radio is the cheapest piece of true safety equipment on your boat, and the most misunderstood. Most boaters own one; far fewer have programmed the one feature that can summon help with a single button press, or know what to say when it matters. Ten minutes with this guide fixes both.
Why VHF Beats Your Phone (It's Not Close)
A phone call reaches one person. A VHF call on channel 16 reaches the Coast Guard and every boat within range simultaneously — and in most emergencies, the help that arrives first is a fellow boater five minutes away, not a response boat dispatched from a station. Add to that: VHF works where cell coverage doesn't, the Coast Guard can direction-find on your transmission even if you can't give a position, and a fixed-mount radio runs off your boat's battery instead of whatever charge your phone has left. Carry the phone. Trust the radio.
Fixed-Mount, Handheld, or Both
- Fixed-mount VHF — 25 watts of transmit power, wired to the boat's battery and a masthead or rail-mounted antenna. Range is determined mostly by antenna height: figure roughly 10–25+ miles ship-to-ship depending on installation, and farther to the Coast Guard's elevated antennas. This is the primary radio for any boat that has the console for it.
- Handheld VHF — 5–6 watts, self-contained, range of roughly 3–8 miles. Indispensable as a backup (it works when the boat's electrical system doesn't — a scenario worth taking seriously on any boat), and as the primary for dinghies, PWCs, and kayaks. Buy one that floats and is waterproof-rated; in 2026 there's no reason to buy one that isn't.
The antenna matters more than the radio. VHF is line-of-sight, so a $150 radio with a quality, properly installed 8-foot antenna will dramatically outperform a $400 radio with a corroded connector and a cheap whip. If your transmissions are weak, look at the antenna, cable, and connections before blaming the radio.
The Channels That Matter
- Channel 16 — Distress, safety, and hailing. This is the channel you monitor whenever the radio is on (it's the law for many vessels and good practice for all). Hail another boat here briefly, then immediately switch to a working channel. No conversations, no radio checks, no kids playing with the mic.
- Channel 9 — Secondary hailing channel for recreational boats in many areas; takes traffic off 16.
- Channels 68, 69, 71, 72, 78A — Recreational working channels. This is where the actual conversation happens after you hail on 16 or 9.
- Channel 13 — Bridge-to-bridge navigation, used by commercial vessels at low power. If you need to coordinate passing with a tug or ship, this is where they're listening.
- Channel 22A — Coast Guard working channel. After they answer you on 16, they'll typically move you here.
- WX channels — Continuous NOAA weather broadcasts, covered in our marine weather guide.
Radio checks: don't do them on 16. Use an automated radio check service where available (Sea Tow operates one on designated channels in many areas) or a working channel. And do one regularly — a radio that hasn't been verified is a radio you're hoping works.
DSC and Your MMSI: The Button Most Boaters Never Activate
Every fixed-mount VHF sold in the U.S. for years has included Digital Selective Calling (DSC) — and a red, covered distress button. Connected to GPS (most modern radios have it built in) and programmed with an MMSI number, that button transmits an automated digital mayday carrying your vessel's identity and exact coordinates to the Coast Guard's Rescue 21 system and every DSC radio in range. It keeps repeating automatically. It works if you're too busy fighting a fire, too injured to speak, or too panicked to remember the script.
Without an MMSI programmed, the button does nothing. This is the single most common gap in recreational radio setups, and closing it is free:
- Get an MMSI: recreational boaters staying in U.S. waters can register free through BoatUS or Sea Tow. If you cruise to Canada, Mexico, or beyond, get your MMSI through an FCC ship station license instead — domestic-issued MMSIs aren't valid internationally.
- Connect the GPS: if your radio doesn't have internal GPS, wire it to your chartplotter. A DSC distress alert without a position is a fraction as useful.
- Enter it carefully: most radios only allow one or two MMSI entry attempts before requiring a factory reset, so type slowly and double-check.
Distress Calls: Mayday, Pan-Pan, Sécurité
Three levels, in descending urgency — all on channel 16 at high power:
- Mayday — Grave and imminent danger to life or the vessel: fire, flooding you can't control, person overboard you can't recover, medical emergency. The script: "Mayday, Mayday, Mayday. This is [boat name], [boat name], [boat name]. Mayday, [boat name]. Position [GPS coordinates, or distance/bearing from a landmark]. We are [nature of emergency]. [Number] persons aboard. [Boat description]. Over." Then release the mic and listen. Repeat if no answer.
- Pan-Pan (pronounced "pahn-pahn") — Urgent, but not immediately life-threatening: engine failure drifting toward a hazard, a medical situation needing advice, taking on water that the pumps are handling. Same structure, "Pan-Pan" three times.
- Sécurité (pronounced "say-cur-i-tay") — Safety broadcast: a hazard to navigation, a large debris field, a tow exiting a narrow channel.
Two things worth drilling into everyone aboard: where the radio is and how to make a Mayday call — because the most likely person to need the radio is whoever's left functional when the skipper isn't. Taping a Mayday script card next to the radio costs a dollar and removes the panic factor entirely. And know that false distress calls are a federal crime with serious penalties; the red button has a cover for a reason.
Etiquette and Habits That Mark a Competent Operator
- Listen before transmitting — you can't hear who you're stepping on while your mic is keyed.
- Low power (1 watt) for close-range talk; high power (25 watts) for distance and all distress traffic.
- Hold the mic an inch or two from your mouth and speak across it, not into it. Slowly. Position and boat name are useless if they're garbled.
- Keep working-channel conversations short and operational. VHF is a party line, not a phone.
- Monitor 16 whenever you're underway. The life you help save will most likely be someone else's — relayed Maydays from nearby boaters are how a lot of rescues start.
Quick FAQ
Do I need a license for a marine VHF?
Not for recreational use in U.S. waters. You'll need an FCC ship station license if you visit foreign ports, including Canada and Mexico. Either way, get an MMSI and program it — free through BoatUS or Sea Tow for domestic boaters.
What's an MMSI and why does it matter?
A nine-digit identity number for the DSC system. With it programmed and GPS connected, the red distress button sends an automated mayday with your identity and exact position. Without it, the most powerful safety feature on your radio is dead weight.
Is VHF really better than a cell phone in an emergency?
Yes. Channel 16 reaches the Coast Guard and every nearby boat at once, works beyond cell coverage, and lets rescuers direction-find on your signal. The phone reaches one person and dies in saltwater. Carry both; rely on the radio.
How do I make a Mayday call?
Channel 16, high power: "Mayday" three times, boat name three times, then position, nature of the emergency, people aboard, and boat description. Then listen, and repeat if needed. Reserve Mayday for grave and imminent danger; use Pan-Pan for urgent-but-not-dire situations.
This guide is general boating education. VHF channel usage can vary by region, and regulations change — confirm current FCC and Coast Guard requirements at navcen.uscg.gov.