Digicel reported on Monday there were two submarine cable cuts on the Tonga Cable and its domestic extension after the massive volcano eruption in Tonga. The cable repair ship CS Reliance owned by SubCom has been activated to undertake the repair.

The first cable cut is on the Tonga-Fiji Submarine Cable System (also known as Tonga Cable), positioned at approximately 37km offshore from Tonga, between Tonga Cable Limited (TCL) cable landing station in Sopu, Tongatapu and FINTEL cable landing station in Suva, Fiji. The second cable break is on the domestic cable which is about 47km away from Sopu, quite near the area of the recent volcanic activity. There might be more cuts.

Tonga cable
Submarine cables connecting Tonga


The Tonga-Fiji Submarine Cable System (or Tonga Cable) is the only one international cable connecting Tonga to the rest of the world. It spans 827km linking Nuku'alofa, Tonga and Suva, Fiji, and connects to the world through Southern Cross Cable Network and other cables at the Cable Landing Station in Suva, Fiji. And the Tonga Cable has an domestic extension from Tongatapu Isaland to Vava’u (additional 348 km) and Ha’apai (a further 58 km).

The state-owned Tonga Cable Limited (TCL) owns and operates the international Tonga-Fiji Submarine Cable System and its domestic extension. 

Digicel Tonga Limited (Digicel) owns minority stake in TCL. Digicel Tonga Limited is part of Digicel Pacific Limited, wholly-owned subsidiary of Digicel Group Holdings Limited (DGHL) which operates in 32 markets in the Caribbean, Central America and Pacific. In October 2021, Telstra acquired Digicel Pacific Limited for US$1.85 billion.

Digicel said its domestic network is now active in Tongatapu, the main island of Tonga. Digicel’s engineers and the technical team are working on the issues and hope to have them resolved in the shortest time possible.

TCL has met with the cable repair company SubCom, which was already in motion to begin the task of repairing the cable, the cable repair ship CS Reliance owned by SubCom has been activated to undertake a full fault assessment as well as determine the safety of a possible cable repair. 

Before the volcano eruption, CS Reliance anchored off Port Moresby in Papua New Guinea, more than 4200km away from Tonga. The site conditions in Tonga have to be assessed thoroughly because of volcanic activities and the cables are very near the volcanoes, especially the domestic cable.

CS Reliance has to travel to Samoa first to pick up their equipment and some spare stuff there. The preparation to come to Samoa is not an issue it will take three to four days and it won't take long to pick up stuff in Samoa.

It is said that the ship is not expected to reach Tonga until Feb. 1, after a voyage of more than eight days. Then it will perform the difficult task of retrieving two sections of damaged cable from the ocean floor and splicing in replacements, with the threat of further volcanic activity ever-present.

The cost for repairs is high, with daily costs for the ship tasked with fixing the cable, the CS Reliance, at between $35,000 and $50,000.

According to New Zealand’s Foreign Ministry, SubCom has estimated that it will take at least four weeks to restore the connection. Communications with Tonga will relies on limited satellite channels during this period.


Update 1: 

The Tonga Cable (international connection to Fiji) was repaired on Feb. 22, 2022. 

Update 2: 

The Tonga Cable Domestic Extension may take a year to fix.

The south end of the broken cable was found 31km from Tongatapu and the north end was located about 136km from Tongatapu. There is gap of around 110km between the two broken ends. It has attempted to recover the middle section but it appears that the cable has been deeply buried under debris from the volcano eruption of 15 January. Without proper survey equipment it is hard to tell what has happened to the cable system. Water depth in this area is between 1.6 to 1.8km. To repair the cable, Tonga Cable Limited may need to order up to 110km cable from ASN, which takes 6-9 month to manufacture and deliver 

The seabed around the Hunga Tonga - Hunga Ha'apai volcano changed dramatically during the eruptions, and the domestic cable was laid close to it. Tonga might have to rethink whether it's safe to lay a new cable in the same place.

Update 3: 

Repairs on the domestic submarine cable system connecting Tongatapu to Ha’apai and Vava’u were completed and back in service on Wednesday night, 12 July 2023, after it was destroyed by the Hunga-Tonga Hunga-Ha’apai volcanic eruption in January 2022. Over 108 kilometers of cable was used for the repair.

It took almost 18 months to repair the Tonga Cable Domestic Extension.