AIS Class M Explained in 2026: What Changed for MOB Beacons in Europe (and Why It Matters)

If you carry an AIS man overboard (MOB) beacon in your lifejacket, or are in the market for a new AIS MOB, you may be aware of new regulations that came into effect as of 1 January 2025: AIS Class M Regulation.

Why the Regulation Was Introduced

Before Class M, many AIS MOB devices simply transmitted an AIS message without interacting with other communication systems onboard vessels. Over time, regulators identified two growing issues:

• AIS Channel Congestion – AIS Channels 1 and 2 are primarily intended for vessel traffic and safety-related communications. However, increasing numbers of autonomous maritime radio devices (AMRDs) such as fishing gear markers and AIS beacons were beginning to flood the network with signals. This raised concerns that critical navigation data could become harder to detect or prioritise.
• Limited Alerting Capability – Earlier AIS-only MOB devices relied on nearby vessels noticing the AIS target appearing on their chartplotter. In busy or stressful situations, this alert might go unnoticed. By requiring Digital Selective Calling (DSC) distress alerts, the Class M standard ensures that nearby VHF radios sound an audible alarm, significantly increasing the chance that the emergency will be recognised immediately.

While the Ocean Signal MOB1 does incorporate DSC distress alerting (it contains a DSC transmitter), it does not contain a DSC receiver (making the MOB1 non-Class M compliant). Based on the Class M regulation that came into effect as of January 1, 2025, Ocean Signal introduced the MOB2 at that time in order to have a Class M AIS MOB option available. The MOB2 contains both a DSC transmitter and receiver and is thereby capable of not only transmitting an AIS MOB message and DSC distress signal message, but also capable of receiving confirmation that the distress alert has been acknowledged.

Are Class M AIS MOB required everywhere in Europe (and the UK)?

One of the most common questions since the introduction of Class M is whether existing AIS MOB devices can still be used. The answer varies depending on the country, but the overall trend is toward full Class M compliance. In several European nations, non-Class M compliant devices can no longer be sold or licensed, and in some cases their use has already been prohibited. The significance of implementation of the Class M regulation for existing MOB1 owners is that MOB1 beacons may no longer be used in countries that have implemented the new regulation. Click here to access a list of European countries showing where the Class M regulation has been implemented.

Do I need to throw away my older AIS MOB beacon?

If you already own a legacy AIS MOB beacon (such as a rescueME MOB1,) it may still technically function (AIS is AIS), but it may not be compliant in jurisdictions that restrict non-Class M devices.

Also worth remembering: in a real distress situation, the aim is saving life. The point of Class M is to make alerts more reliably noticed, not to discourage carrying safety gear.

How to tell if a beacon is Class M

Look for one of the following in the spec sheet/manual:

• Wording referencing compliance with “Class M Regulation“
• Wording referencing compliance with ECC/DEC/(22)02 (also known as the Class M Regulation)

What Class M changes in a real MOB (why sailors like it)

When someone goes overboard, speed matters. In moderate seas you can lose sight of a person fast.

A Class M AIS MOB device:

1. Creates an AIS MOB target on plotters/AIS receivers within VHF range so boats can navigate back to exact coordinates.
2. Triggers a DSC alarm on VHF radios in range, which is harder to miss than a silent AIS icon.
3. Is capable of receiving confirmation that the distress alert has been acknowledged.

Enforcement and real-world reality (UK & EU)

At the moment, there are no widely reported, clearly documented public cases of leisure sailors being caught or fined specifically for using a non-Class M AIS MOB beacon in UK/EU waters since the January 2025 change. (That doesn’t prove none exist, just that they’re not turning up in public regulator notices or mainstream boating coverage.)

In the UK, at the time of initial publishing of this blog (March 2026), The Office of Communications (Ofcom) website states that licensees can continue to use non-Class M MOB devices on AIS 1 & AIS 2 after 31 December 2024 under the Ship Radio Licence / Ship Portable Radio Licence, while Ofcom brings forward proposals to phase out that authorisation. (www.ofcom.org.uk).

What this means, don’t panic about existing kit in the UK, but new purchases should be Class M to stay future-proof. As mentioned previously, Class M Regulation has already been implemented in numerous European countries. Click here to access a list of European countries showing where the Class M regulation has been implemented.

What the industry has been saying since launch

The consistent themes from boating press, manufacturers, and the wider marine electronics world:

• “Class M is the direction of travel—buy it if you’re buying now.” Boating media have framed Class M as the new rulebook for AIS MOB beacons in Europe, with an emphasis on choosing Class M for future compliance. (Yachting World)
• “The real upgrade is DSC + AIS: audible alarm + visual target.” Industry messaging heavily focuses on the practical benefit: Class M devices combine the AIS target (plotter/chart visibility) with a VHF DSC alert that can trigger loud alarms on radios in range. (Yachting World)
• “This is about protecting AIS channels from congestion.” Many industry explainers cite the rise of non-distress “off-ship” AIS transmitters (markers, etc.) and the need to keep AIS reliable for safety and navigation.
• “Channel 2006 is controversial because it’s not routinely monitored.” A key talking point is that Channel 2006 (160.900 MHz)—used for other AMRD categories—won’t be monitored by general shipping/coast stations as part of GMDSS, which is why Class M (AIS 1/2 + DSC 70) is viewed as the “right” MOB pathway. (docdb.cept.org)
• “There’s still confusion—especially around where rules apply and what happens to older devices.” The UK conversation in particular has revolved around Ofcom’s transitional position (continued use under licence now, proposals to phase out), which has reduced “panic” but increased “what exactly should I buy next?” questions. (www.ofcom.org.uk)

Compatibility and setup tips

• Check your VHF DSC radio and plotter/AIS receiver are set up correctly (MMSI entered where required, DSC enabled, alarms configured).
• Older radios may behave differently; always verify compatibility with your electronics manufacturer.
• Install and test your beacon exactly as the manual describes, especially if it’s designed to auto-activate on lifejacket inflation.

Ocean Signal and Class M

Ocean Signal’s rescueME MOB2 and MOB2 Sailing Safety Kit is designed to meet ECC/DEC/(22)02 (Class M) and combines AIS positioning with VHF DSC alerting for rapid local response.