The 'hero' ship fixing Africa's internet blackouts - the BBC goes aboard
Just a month later, in March 2024, a separate set of breaks in the Wacs, Ace, Sat-3, and MainOne cables off the coast of West Africa caused severe internet blackouts across Nigeria, Ghana, Ivory Coast and Liberia.
Anything that required the internet to function felt the strain as repairs stretched on for weeks.
Then in May, yet another setback: the Seacom and Eassy cables suffered damage off the coast of South Africa, hitting connectivity in multiple East African nations once again.
Such faults are detected by testing electricity and signal strength transmitted through cables.
"There may be 3,000 volts in a cable and suddenly it drops to 50 volts, this means there's a problem," explains Loic Wallerand, the ship's chief of mission.
There are local teams with the capacity to deal with faults in shallow waters, but if they are detected beyond a depth of 50m (164ft), the ship is called into action. Its crew can fix cables deeper than 5,000m below sea level.
The repair witnessed by the BBC off Ghana took over a week to deal with, but most internet users did not notice as traffic was redirected to another cable.
The nature of every repair depends on the part of the cable that is damaged.
If the fibreglass at the core breaks, it means the data cannot travel along the network and needs to be sent to another cable.
But some African countries have only one cable serving them. This means a cable damaged this way leaves the affected area without the internet.
At other times, the protective layers of the fibre could be damaged, meaning data transmission still occurs, but with a lower efficiency. In both cases, the crew must find the exact location of the damage.
In the case of broken fibreglass, a light signal is sent through the cable and through its point of reflection, the crew can determine where the break is.
When the problem is with the cable's insulation - known as a "shunt fault" - it becomes more complicated and an electrical signal has to be sent along the cable to physically track where it is lost.
After narrowing down the possible area for the fault, the operation moves to the ROV team.
Built like a bulldozer, the ROV, weighing 9.5 tonnes, is lowered under water from the ship where it is guided down to the ocean floor.
About five crew members work with a crane operator to deploy it - once it is released from its harness, called the umbilical cord, it floats gracefully.
"It doesn't sink," says Mr Heald, explaining how it uses four horizontal and vertical thrusters to move in any direction.
The ROV's three cameras allow the team onboard to look for the precise location of faults as it moves to the ocean bed.
Once found, the ROV cuts the affected part using its two arms, then ties it to a rope that is dragged back to the ship.
Here the faulty section is isolated and replaced by splicing and joining it to a new cable - a process that looks like welding and which took 24 hours in the case of the operation witnessed by the BBC.
Afterwards the cable was carefully lowered back to the ocean bed and then the ROV made one final journey to inspect that it was well placed and take coordinates so maps could be updated.
When an alert is received about a damaged cable, the Léon Thévenin crew is ready to sail within 24 hours. However, their response time depends on several factors: the ship's location, the availability of spare cables and bureaucratic challenges.
"Permits can take weeks. Sometimes we sail to the affected country and wait offshore until the paperwork is sorted," Mr Wallerand says.
On the average, the crew spends more than six months at sea every year.
"It's part of the job," says Captain Thomas Quehec.
But talking to the crew members between tasks, it is hard to ignore their personal sacrifices.
They are drawn from different backgrounds and nationalities: French, South African, Filipino, Malagasy and more.
Adrian Morgan, the ship's chief steward from South Africa, has missed five consecutive wedding anniversaries.
"I wanted to quit. It was difficult to stay away from my family, but my wife encouraged me. I do it for them," he says.
Another South African, maintenance fitter Noel Goeieman, is worried he may miss his son's wedding in a few weeks if the ship is called out to another mission.
"I've heard we might go to Durban [in South Africa]. My son is going to be very sad because he doesn't have a mum," says Mr Goeieman, who lost his wife three years ago.
"But I'm retiring in six months," he adds with a smile.
Despite the emotional toll, there is camaraderie onboard.
When off-duty, crew members are either playing video games in the lounge or sharing meals in the ship's mess hall.
Their entry into the profession is as diverse as their background.
While Mr Goeieman followed his father's footsteps, chief cook, South African Remario Smith, went to sea to escape a life of crime.
"I was involved in gangs when I was younger," Mr Smith says, "My child was born when I turned 25, and I knew I had to change my life."
Like the others onboard he is appreciative of the role the ship plays on the continent.
"We are the link between Africa and the world," says chief engineer Ferron Hartzenberg.
Additional reporting by Jess Auerbach Jahajeeah.
Getty Images/BBC
