Taiwan-Matsu No. 4 Cable Enters Service

Publication Staff, Ministry of Digital Affairs Taiwan
September 18, 2026

Taiwan's Ministry of Digital Affairs says the Taiwan-Matsu No. 4 submarine cable has been completed and put into service, giving the Matsu islands another route to Taiwan's main island. Chunghwa Telecom built the nearly 300 km link with ministry support under a forward infrastructure program. The route reaches Dongyin, Nangan and Xiju. This is an operational activation, rather than a plan or construction start: the ministry says aggregate Taiwan-Matsu transmission capacity rises to about 1.9 Tbps with the fourth cable operating.

The design addresses the physical exposure of island links. According to the ministry, planners evaluated shipping lanes and fishing activity, selected double-armored cable and set a burial-depth target of 2.5 metres to reduce damage from vessels and fishing gear. The release also describes an automatic warning mechanism that combines vessel Automatic Identification System data with AI identification, in cooperation with the coast guard. The stated burial depth is a design target in the announcement; the ministry does not provide a route-wide as-built burial survey or a measured protection result.

The new route joins Taiwan-Matsu No. 2 and No. 3, as well as microwave and satellite paths, in a broader backup architecture for the offshore islands. More cable paths give operators additional options when a span fails, while radio and satellite services can help preserve essential communications. The ministry connects this approach to government coordination, disaster response, medical services and public connectivity. It does not claim that the fourth system alone removes outage risk. The confirmed gain is more aggregate capacity and an additional submarine route after earlier Matsu cable disruptions.

The ministry marked the activation at a ceremony in Lienchiang County on September 18. Taiwan-Matsu No. 4 is now reported in service, and the release identifies no remaining commissioning step for this system. Two other island cable projects, Taiwan-Penghu No. 4 and Penghu-Kinmen No. 4, are expected to be completed before year-end; those are separate projects and future milestones. For cable owners, today's verified change is an additional working Matsu path. Its protection design is described as part of the build, while future performance will depend on operation and maintenance.

View source