Jeju-Mainland 2

Overview

Jeju-Mainland 2 is a domestic submarine cable system operating entirely within South Korea. Spanning 191 km, it connects two landing points on the South Korean mainland and coast, serving the intra-national corridor that links the country's southern coastal regions. As a domestic cable, it differs from the predominantly international systems that make up much of South Korea's submarine cable infrastructure.

Route and Landings

Both landing points are located in South Korea. The cable comes ashore at Goheung and at Goseong-ri, two locations along the southern coast of the Korean peninsula.

Ownership and Operators

Jeju-Mainland 2 is owned by KT, the South Korean telecommunications carrier formerly known as Korea Telecom. KT is one of South Korea's principal fixed-line and broadband network operators and has maintained a long-standing presence in the country's submarine cable infrastructure.

Status and Timeline

The cable entered service in 1996, making it 30 years operational. It holds the distinction of being among the earliest submarine cables to land in South Korea, with 1996 marking the country's first recorded submarine cable ready-for-service year. The cable remains in service.

Regional Context

South Korea's submarine cable network comprises 14 systems landing across 10 landing points, with an average cable length of approximately 9,233 km. Jeju-Mainland 2, at 191 km, is notably shorter than the regional average, reflecting its domestic rather than international function. It is longer than roughly 15 percent of the other cables touching South Korea, a figure that underscores how the country's cable portfolio is dominated by long-haul transoceanic systems.

The regional peers serving South Korea include systems such as EAC-C2C, APCN-2, Trans-Pacific Express (TPE), New Cross Pacific (NCP), E2A, and SJC2 — all of which are intercontinental cables of considerably greater length. Jeju-Mainland 2 predates all of these systems, having entered service before any of them reached readiness.

Strategic Role

As a short domestic cable connecting two points along South Korea's southern coast, Jeju-Mainland 2 serves intra-national connectivity needs rather than international traffic exchange. Its early RFS date of 1996 places it at the foundation of South Korea's submarine cable development, preceding the wave of large-scale international systems that subsequently landed in the country. The cable's 191 km length and two landing points at Goheung and Goseong-ri define a focused, point-to-point domestic link under the operation of KT.