Sea change in overboard recovery: Zelim advances offshore safety
Iain Hoey
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Sam Mayall, CEO of Zelim, outlines how AI-enabled detection, unmanned rescue craft and automated retrieval systems are reshaping man overboard response in the maritime sector
It doesn’t take long for someone in the water to be overcome by cold or swept away from the vessel they fell from.
Increasingly, technical solutions are helping crews respond more quickly.
At around 3:40am, a cruise ship passenger was woken by the emergency announcement: “Oscar! Oscar! Oscar! Off the port side.
Man overboard.” The early hours are a common time for these incidents, and by the time the passenger heard the alert, the ship’s crew would already have begun their search and rescue procedures.
In this case, in August 2024, after several days of effort by vessels in the vicinity and coast guard assets launched to sea and air, the search for the missing passenger was unsuccessful.
The first challenge with a person overboard is knowing when and where they fell.
The second is finding them once they have entered the water.
They can drift quickly and be lost to sight, obscured by darkness, waves, glare, or sea spray.
The search area can span tens of square kilometers before rescue authorities are even notified.
And if there’s no clear confirmation that someone has gone overboard, rescue efforts can be delayed while the vessel is searched.
“This is typical of cruiseships which are not equipped with automatic man overboard (MOB) systems; instead of immediately searching in the water when a guest or ship employee goes overboard, the ship will waste time looking on the ship for the missing crew member,” said maritime lawyer Jim Walker on social media in response to a May 2024 incident.
There are MOB detection systems available on the market, but cruise companies have been wary of the false alarms created by, for example, a seabird flying near the vessel.
The ISO standard 21195 was published in 2020 to help overcome the problem.
It sets a minimum performance rate of 95% detection probability, and systems should not generate more than one false alarm a day.
That way crew members don’t become alarm-weary and have an alerting system they can trust.
Minutes matter
The UK Marine Accident Investigation Branch (MAIB) has reported that, on average, it takes under 11 minutes for a person who has fallen overboard into cold water to become unresponsive.
An analysis of 20 accidents that occurred between 2017 and 2021 showed that this decreases to just four minutes as the water becomes colder or the sea rougher.
Recovery becomes much more difficult if the casualty is unresponsive, and the success rate for person-in-water rescue is not high anyway.
Industry reports indicate that only around 20% of passengers that fall from cruise ships survive.
Of the 308 person overboard incidents from ships, fishing vessels and recreational boats reported to MAIB between 2015 and 2023, 40% lost their lives.
The problem is not confined to ships.
Earlier this year, Edinburgh-based equipment manufacturer Zelim’s intelligent MOB detection solution, ZOE, was deployed onboard the jack-up drilling rig VALARIS Stavanger.
ZOE, which in September received Approval in Principle from Lloyd’s Register, transmits an automatic alert to the radio operator who can then see a 10-second video clip of why the alert was triggered whilst simultaneously viewing live footage.
The system logs the position of the rig and the person overboard and provides the radio operator with a mayday call script and action checklist.
Glen Spearman, Offshore Installation Manager onboard VALARIS Stavanger, said: “The North Sea is a harsh weather environment that can change quickly.
If someone ends up in the water, the alarm is raised, and one person acts as a spotter to maintain visual contact.
We are totally reliant on line of sight.
ZOE gives us a 360-degree view from the rig at any one time.”
The installation features seven infrared and optical cameras placed around the rig, each with AI target identification functionality.
A cruise ship might have 10 such camera systems installed, all controlled by the ZOE software platform.
While other systems on the market typically only detect the person overboard whilst falling, which accounts for the first few seconds of the incident life cycle, ZOE not only detects the fall but then continues to track the person in the water as they drift away from the vessel.
ZOE is unique in that it can be paired with two industry-first systems also developed by Zelim’s CEO Sam Mayall and his team, with input from the UK Maritime and Coastguard Agency and the US Coast Guard.
In September 2024, the company launched the world’s first unmanned remotely controlled rescue vessel.
Specifically designed for rapid deployment from a ship to recover both conscious and unconscious casualties, the GUARDIAN fast rescue craft can operate in sea conditions that would be too dangerous for conventional manned recovery solutions.
Hinged to its bow is SWIFT, a Lloyd’s Register approved treadmill-like conveyor belt system.
Once the rescue vessel nears the casualty, SWIFT is lowered into the water and its conveyor belt activated.
With traction, casualties are then pulled free of the water.
The technology has a pulling weight rated at 275kg
The three innovations can be implemented as an integrated system or installed and operated independently.
Mayall, a former navigating officer aboard offshore support vessels, was motivated to develop the new technology and start Zelim after being personally involved in a response to a man overboard incident where they unfortunately found the person too late.
He notes that 80% of deaths from drowning occur in the first 30 minutes.
A cruise ship sailing at 25 knots can travel three miles in six minutes.
It’s therefore important that the Officer-on-Watch is given the information they need to quickly and confidently initiate their rescue protocol.
Mayall says: “In emergency situations, people should revert to training, but they don’t always do that.
Instead, they might feel confounded by too many alarms and different sources of information on the bridge.
Our solutions are very intuitive and follow a very logical process to help guide the operators through what their company’s procedures call for.”
That intuitiveness includes the operation of the rescue craft and the use of its two-way radio, so even if it is unmanned, a rescued person can easily work out how to contact their rescuers.
Mayall sees a growing need for rescue technology as the booming cruise industry and the growing blue economy means more people at sea.
“With Zelim, the maritime and offshore industries now have a system capable of rapidly rescuing people in all weather conditions,” he says.
“Given that more than 1,000 people already fall overboard annually, every shipowner should be using the technology now available as a matter of course.”
The maritime safety solutions innovator is currently cooperating with CASARA, Canada’s Civil Air Search and Rescue Association, following the successful demonstration of ZOE during the National SAREX 24 Search and Rescue exercise.
The company is also close to finalising a pilot installation aboard a cruiseship, and numerous Port Authorities, wind farm operators and coastguards have taken part in demonstrations of both ZOE and SWIFT.