What the M-Class?! AIS Beacons Get a New Rulebook

If you’re like me and you’ve got a healthy collection of gadgets clipped, zipped, and stashed around every bit of your foulies, then you’ve probably already clocked a few personal AIS beacons in your time. Little lifesavers, they are, quiet until they really, really matter. There’s some excellent stories of lives being saved by them in some of the most dire of circumstances.

But now there’s a new label on the scene, since January 2025: Class M.

And if you’ve been wondering, “Is this another bit of EU meddling or does it actually matter?” – let me explain, sailor-to-sailor.

What is Class M?

Class M is the new standard for personal AIS beacons, the little ones you clip into your lifejacket so that if you end up going for an unplanned swim, your exact GPS location pings out to all nearby AIS receivers.
Previously your little AIS beacon would put a circle with a cross up on anyones AIS screen, and hopefully someone might notice it, if noone from your own boat realised you’ve gone overboard.

Now, they include DSC and will ping a DSC alert to all VHF radios within range. You know that really annoying radio squeal you get right as your drifting off during your off watch? Yeah, it’ll wake the dead, so those going overboard will audibly alert all local vessels and not just with a visual mark on the screen. (it does both now)

M stands for “Man Overboard”  and not just metaphorically. These beacons are specifically designed and tested for MOB use, and the Class M label is there to separate the proper kit from the less certified. This doesn’t mean that you must bin all non-M class kit you are already using. If you are sailing outside of European waters, for the moment at least, all of the current beacons on the market are valid. If you are still using a perfectly functioning, older AIS beacon within European waters, no authority is going to punish someone for using a beacon to save a life, just because it’s missing that stamp of approval.

Until now, anyone with a soldering iron and a marketing budget could slap “AIS” on a beacon. Class M certification means it’s gone through proper testing for:

GPS accuracy Signal strength and range Water activation Battery life Compatibility with real-world marine electronics

Why should I care?
Because as of January 2025, in parts of Europe (and likely more places to come), only Class M beacons are allowed to transmit on the AIS channels. If you’re racing, cruising, or just knocking about the Solent with a thermos and a dodgy autopilot, your beacon needs to meet these new standards to stay legal, and useful.

Which beacons are Class M right now?

As of now, two AIS beacons are confirmed to meet the new Class M standard:

sMRT ALERT – robust, water activated, NFC pairing, DSC functionality, and a flat profile that won’t poke you in the ribs.

This beacon is among the first to achieve Class M compliance. It features a flat, slim design and is robustly built. The device is simple to use, offering automatic activation upon water immersion or manual activation via a large button. It transmits AIS signals to nearby vessels and sends DSC alerts to VHF radios. Additionally, it includes NFC capability for smartphone connectivity, allowing users to manage and monitor the beacon through a dedicated app.

Ocean Signal rescueME MOB2 – tiny, tough, fits inside your lifejacket, automatic activation on inflation. NFC pairing.

The rescueME MOBs is the world’s smallest AIS MOB device with integrated DSC. Designed for easy integration into lifejackets, it automatically activates upon inflation, transmitting AIS signals and DSC alerts to nearby vessels. The device also features a high-intensity strobe light for enhanced visibility in low-light conditions.

Both beacons comply with the European Class M regulation (ECC/DEC/(22)02), which mandates that from January 1, 2025, only Class M DSC MOB devices and Mobile AtoN will be permitted to use AIS Channels 1 & 2 in certain European countries. This regulation aims to prevent the AIS system from being overwhelmed by non-ship devices.

 

There’ll be more on the way, but check for the Class M label before you splash your cash. It’s a stamp of quality, not just compliance.

I don’t care how many cup holders your boat has, if you sail with people, or solo, or even just day hop in patchy weather, a Class M AIS beacon should be standard kit.

It’s not just about being legal. It’s about being found fast, by the boats nearest to you, without relying on satellites, search helicopters or hope.

Get one, fit it properly, test it (dry, please), and sleep better knowing that if you do trip over going for a pee on nightwatch, or wobbling about getting onto your boat from your tender after a particularly fund time ashore, then you’ll be found alive so you can laugh about it later.

If you’re looking for more than just an AIS beacon, I’ve gathered a smorgasbord of beacons in my buyers guide to all things beacony. 

 

Original author: Morgan