by Rory Hughes, Technical Director
As Technical Director at Zelim, I am responsible for the research, design and implementation of the hardware, software and systems that we deploy to save lives and protect assets at sea.
In the busy and complex maritime environment, any systems and technology deployed on a vessel should seek to enhance safe and efficient operations, rather than creating obstacles for the vessel crew. But that isn’t always the reality.
The scale of the problem
According to a pioneering research paper published by Lloyd’s Register (LR) in January 2026, maritime vessels can experience thousands of shipboard alarms daily, many of which are false. These excessive alarms routinely overwhelm crews. Lloyds’ research shows that, in some cases, cruise ships have up to 2,600 alarms per day, with peak rates reaching 4,691 alarms in just 10 minutes. This far exceeds the ideal rate of fewer than 30 alarms per hour, a benchmark met by not even half of the vessels studied.
Impact to safety and trust
An excessively high number of false alarms means that, in practice, the very systems intended to enhance safety at sea are effectively eroding it. Every false alarm interrupts the human watchkeepers, eroding their trust in the systems and leading to a potentially dangerous normalisation of the abnormal.
One prominent safety-critical alarm is the man-overboard (MOB) detection system. These specialised safety technologies are designed to immediately detect, track and assist in rescuing individuals who have fallen from a vessel into the sea. MOB detection systems, like many of the alarm systems onboard vessels, have often generated a high rate of false positive alarms, often at unacceptable levels. The resulting lack of trust can ultimately cause users to turn off the systems, rendering them useless. Legacy MOB systems use basic decision logic which is not sophisticated enough to capture the complexities of the modern maritime environment, leading to unnecessary alarms. This can diminish trust and credibility in systems over time, and also has the potential to create further risks to the safety of personnel and operations.
Safety systems should not have to be a compromise. The maritime industry should be exploring all possible solutions to address nuisance alarms.
Overcoming the challenge
Ship owners need to prioritise tech solutions that are proven to have very low false positive alarm rates. This should take place at the design stage, when ships are being built and upgraded. By installing systems that are already proven and deployed in the maritime sector, ship owners and crew can rely on and benefit from MOB safety measures without the burden of excessive false alarms.
The current industry is utilising modern algorithms and software to develop more advanced systems which exhibit very low false positive alarm rates. In the world of man-overboard detection, machine learning has helped advance the products on the market significantly in recent years, meaning that for some of the most recent innovations, the risk of false positives is negligible.
The LR paper recommends the maritime industry focus on human-centred design, giving proper consideration to human factors within alarm system design. This means that equipment choices should reduce crew burden. Ship-builders therefore have a duty to explore modern technology solutions that significantly reduce the burden of false alarms, and in doing so drastically increase safety onboard vessels.
ZOE MOB: a modern solution to rebuild confidence
Already successfully deployed in the cruise and defence sectors, Zelim’s ZOE MOB is a leading example of such a system. ZOE is compliant to ISO 21195, which requires that systems have no more than one false positive per day. The technology uses computer vision with best-in-class sensors and video analytics, and is sophisticated enough to consistently perform well under the threshold of daily acceptable false alarm rates. This brings significant value to operators, giving them confidence that an alarm is genuine and worthy of their attention, rather than their dismissal.
As outlined in the LR report, it is crucial that vessel developers address the detrimental impacts of excessive false alarms. Investing in the installation of technology that attains low false alarms has the potential to transform the customer experience for maritime vessel operators, helping crews to avoid unnecessary distractions and building trust in safety critical systems. Recent breakthroughs in innovation mean that vessel developers now have the technology available to them that can achieve these goals.
