How commercial shipping learned that fewer alarms save more lives – and what pleasure sailors can take from a billion dollars of maritime research.
The Organisation That Investigates Every Accident
When a commercial vessel runs aground, collides, or sinks, it doesn’t simply become a tragic story that fades with time. The International Maritime Organization – the United Nations agency responsible for shipping safety – ensures that every significant incident is investigated, documented, and analyzed. The findings become part of a global knowledge base that shapes future regulations.
This stands in stark contrast to pleasure boating. When a sailing yacht goes missing or a motorboat capsizes, the investigation often ends with basic facts: weather conditions, probable cause, case closed. There is no global body tracking patterns, no systematic analysis of what equipment might have prevented the tragedy, no requirement that lessons learned be incorporated into future vessel designs.
Commercial shipping’s obsession with investigation has paid extraordinary dividends. Despite a global fleet that has grown massively and vessels that have become exponentially more complex, the rate of serious casualties has dropped by over 50% since 2000. This improvement didn’t happen by accident – it came from studying accidents.
The Problem They Discovered: Alarm Chaos
As investigators dug into incident after incident through the 1990s and 2000s, a troubling pattern emerged. Ships were becoming safer on paper – more sensors, more monitoring, more redundancy – yet officers were still missing critical warnings. The culprit wasn’t faulty equipment or poorly trained crews. It was noise.
A 2018 study by Lloyd’s Register documented what investigators had been seeing in accident reports: the average commercial bridge now generates 74 alarms per hour. Engine rooms were worse – peaks of 22,500 alarms per day during port operations. The human brain simply cannot process that volume of alerts. Officers were doing what any human would do: tuning them out.
“When we reviewed the bridge audio recordings, we could hear alarms sounding continuously for eleven minutes before the grounding. The officer on watch had stopped responding to them after the first two minutes.”
– Marine Accident Investigation Branch, Beaumaiden Report (2021)
The Karen Danielsen case in 2005 became a turning point. This Danish cargo vessel ran aground in the North Sea despite having all the modern navigation equipment that should have prevented it. The investigation revealed that the officer on watch had been dealing with a cascade of low-priority alarms – bilge level warnings, minor temperature deviations, maintenance reminders – when the critical depth alarm sounded. It was just another beep in a symphony of beeps. He didn’t register its significance until the ship shuddered onto the sandbank.
The Elegant Solution: Make Some Alarms Silent
The IMO’s response, developed over years of research and debate, was counterintuitive: the way to make ships safer was to have fewer alarms, not more. In 2010, they adopted Resolution MSC.302(87), known as the Bridge Alert Management guidelines – BAM for short.
The genius of BAM lies in its simplicity. Instead of treating every sensor reading as equally urgent, the system categorizes alerts into four distinct levels:
Emergency
Immediate danger to human life or vessel. Loud, insistent, impossible to ignore. Think: fire, flooding, man overboard.
Alarm
Conditions requiring immediate attention but not immediate danger. Distinct audio pattern. Requires acknowledgment.
Warning
Conditions requiring attention but not immediately. Softer audio, can be silenced once acknowledged.
Caution
Awareness conditions. Visual indication only – no sound at all. The crew should know, but doesn’t need to be interrupted.
That last category – silent cautions – was revolutionary. For decades, the instinct in maritime safety had been “if it’s worth monitoring, it’s worth alarming.” BAM said: wrong. Some things need to be displayed but should never make a sound. The bilge pump running for routine water removal? A fuel tank at 30% capacity? These are cautions. Display them. Don’t beep.
Central Intelligence: The CAM System
BAM also introduced the concept of Central Alert Management – a single system that coordinates all alerts across the vessel. Before CAM, the radar might be screaming about a close contact while the engine room was demanding attention for a temperature spike while the fire system was testing itself. Each system shouted independently, creating chaos.
With CAM, all alerts flow through one intelligent hub. It knows what’s happening across the entire ship. If multiple conditions occur simultaneously, it presents them in priority order. If an officer acknowledges an alarm, the acknowledgment propagates to all displays. If a critical alert is ignored for too long, it escalates – first to the bridge, then to the captain’s quarters, then to the chief engineer.
The system became mandatory for all new commercial vessels from 2021. The results have been striking. The M/V Priscilla grounding investigation in 2018 had noted “alarm fatigue as a contributing factor.” By 2023, such findings had become rare in investigation reports. Ships weren’t just equipped better – they were being operated better, because crews could finally hear what mattered.
What This Means for Pleasure Sailors
You’re not bound by IMO regulations. Your 40-foot sailboat doesn’t need a Central Alert Management system. But the principles that emerged from decades of commercial maritime research apply just as much to your vessel as to a 300-meter container ship.
Consider your current setup. How many devices can make noise? Chartplotter depth alarms. AIS collision warnings. Engine temperature. Bilge pump. VHF radio. Smoke detector. CO detector. Each manufacturer, designing in isolation, made their product as noisy as possible – because that’s how they show they’re keeping you safe.
Now imagine you’re approaching a tricky harbor entrance at dusk, wind picking up, crew tired. The bilge pump kicks on for a routine cycle – beep. The depth alarm triggers briefly as you cross a shallow spot you already knew about – BEEP. The AIS shows a ferry that you’ve been tracking for twenty minutes – BEEP BEEP. By the time the engine temperature warning sounds – the one that actually matters, the one telling you your cooling water intake is clogged with weed – you’re already conditioned to ignore it.
Practical Takeaways
- Audit your alarms. Spend a day passage noting every beep. Which ones made you look? Which ones did you ignore?
- Create hierarchy. Turn off audible alarms for routine conditions. Let the bilge pump run silently – check it visually during your normal rounds.
- Distinguish the critical. The alarms that should scream are: fire, flooding, AIS collision within 10 minutes, engine shutdown. Everything else should either be silent or use a distinctly softer tone.
- Don’t add more monitors – add smarter ones. A single well-designed system that prioritizes alerts is worth more than five independent alarms all shouting at once.
Commercial shipping learned a hard lesson over thirty years of accident investigations: safety doesn’t come from more warnings, it comes from better warnings. The quieter bridge is the safer bridge. The officer who responds to every alarm is the officer who has learned which alarms deserve response.
We have the benefit of all that research, all those investigations, all that accumulated wisdom – without having paid the price in lives and lost vessels. The least we can do is listen to what they learned.
Sometimes, the most important safety improvement is knowing when to turn the beeping off.
References
- Lloyd’s Register (2018). “Human Element: Bridge Alert Management and Alarm Fatigue Study.”
- International Maritime Organization (2010). Resolution MSC.302(87): “Adoption of Performance Standards for Bridge Alert Management.”
- Danish Maritime Authority (2006). “Karen Danielsen Grounding Investigation Report.”
- Marine Accident Investigation Branch (2021). “Report on the Grounding of MV Beaumaiden.”
- International Maritime Organization (2009). Resolution A.1021(26): “Code on Alerts and Indicators.”
- IEC 62923-1:2018. “Maritime Navigation and Radiocommunication Equipment – Bridge Alert Management.”
- Bahamas Maritime Authority (2019). “M/V Priscilla Investigation Report.”
- SOLAS Convention, Chapter V, Regulation 19.2 – Requirements for Carriage of Shipborne Navigation Systems.





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