Repairing the Tonga cable

Wonderful article on Reuters (with lovely and very informative graphics) about the work to repair the Tonga cable: The race to reconnect Tonga

The 827 km (514 miles) cable from Fiji to Tonga is one of 436 active undersea cables that connect the globe.
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Most cable damage occurs due to ship anchors or fishing trawlers and occasionally environmental factors such as earthquakes.

Faults are common and typically most traffic would be rerouted to another cable. However, in Tonga’s case, there is only one cable connecting the country.
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The fibre optic cable isn’t easy to fix. A technician splices the glass fibres and uses glue to attach the new section of the cable. This fibre optic splicing can take up to 16 hours and is the most crucial aspect of the repair work.
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A remotely operated vehicle (ROV) may descend to the seabed to inspect and help bury the cable, although they can only work to a certain depth. In the case of the Reliance, the vehicle can descend up to 2,500 meters.