ROV

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.

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.

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.