When someone goes overboard or a vessel is in distress, every second counts. But when it’s dark, stormy, or chaotic, even trained crews can lose visual contact in seconds. That’s why AIS-based emergency devices — like the MOB1 beacon, Search and Rescue Transponder (SART), and AIS Alarm Boxes — are transforming how commercial vessels respond to emergencies.
In this article, we’ll break down how these devices work individually, and more importantly, how they work together as a coordinated lifesaving system.
MOB1: Instant Overboard Alert — Right on the Chartplotter
The MOB1 (Man Overboard Beacon) is a compact device worn by crew members, often integrated into a lifejacket. The moment it hits the water and activates, it sends:
An AIS signal to nearby vessels (up to 5 NM or more)
A DSC distress message to your vessel’s VHF system
This means two things happen simultaneously:
- Your ship sees the MOB location immediately on-screen
- All nearby vessels with AIS can see and respond too
Equipping crew with MOB1 is especially valuable for:
High-speed operations
Night navigation
Short-handed watches
Harsh offshore environments
You’ll find the Ocean Signal MOB1 available at Gaelix Marine Service — a must-have for any serious operator.
SART: A Lifeline When You Can’t Be Seen
While AIS beacons are brilliant for local area responses, Search and Rescue Transponders (SART) step in when you’re further out, especially in SOLAS-class emergencies.
How it works:
A SART activates when it receives a radar signal from a rescue ship or aircraft
It immediately transmits back a signal that displays as 12 dots on the radar screen, pointing rescuers directly to your location
Range: up to 8–10 NM depending on conditions
These are required equipment for many vessels under SOLAS, and they’re incredibly effective in fog, low visibility, or offshore rescues where AIS isn’t enough.
The Ocean Signal S100 is a trusted SART model — compact, durable, and available now at Gaelix Marine Service.
AIS Alarm Box: The Missing Link Between Signal and Response
An AIS beacon is only effective if someone sees it. The AIS Alarm Box ensures that when a MOB device transmits, it’s heard and acknowledged — instantly.
Installed on the bridge or in the wheelhouse, the unit:
Monitors AIS channels 24/7
Triggers a loud audible and visual alarm the moment a MOB signal is received
Shows the exact AIS MMSI of the beacon for fast identification
This device closes the loop between the person in the water and the decision-maker onboard.
If you operate with rotating crew, night shifts, or rely on part-time skippers, the AIS Alarm Box adds a critical safety net to your emergency response.
Working Together: A Chain of Action
Let’s look at a real-life scenario.
A deckhand falls overboard at night:
Their lifejacket auto-inflates and activates the MOB1
The AIS Alarm Box immediately alerts the bridge
Nearby vessels pick up the AIS distress
If a rescue aircraft is involved, the SART beacon provides radar location confirmation
Response time drops from minutes to seconds
That’s the power of an integrated AIS safety system — not just devices, but a complete strategy.
Corporate Insight: Don’t Wait for the Mandate
While some of these tools are not yet required under national law, corporate safety leaders don’t wait for regulations — they lead.
Provide MOB1 beacons for all crew
Keep a SART ready for offshore deployments
Install an AIS Alarm Box on every vessel
Train your crew to interpret and respond to signals fast
Because when someone hits the water, what happens next isn’t theory — it’s action.
Get Your System in Place
At Gaelix Marine Service, we offer full packages for AIS-based safety systems, including:
Ocean Signal MOB1, S100 SART, and AIS Alarm Box
Mounting solutions and accessories
GMDSS-compatible integration
Browse the full selection of Emergency Equipment Devices or reach out for a tailored setup for your fleet.
✅ Final Thought
AIS safety isn’t just about better gadgets — it’s about buying time, saving lives, and making sure no one gets left behind in the dark.
If your vessel runs hard, runs far, or runs at night — your crew needs more than a whistle. They need visibility. They need connection. They need AIS.
