Shikinejima, Japan

Shikinejima, Japan: Submarine Cable Landing Point

Shikinejima is a small volcanic island in the Philippine Sea, situated approximately 160 kilometres south of Tokyo and forming part of the Izu Seven Islands chain within the Izu archipelago. Administered as part of Tokyo Metropolis, the island belongs to the village of Niijima alongside the larger neighbouring island of Niijima. Despite its modest size, Shikinejima serves as a submarine cable landing point, connecting it to Japan's broader domestic telecommunications network.

One submarine cable lands at Shikinejima. The 5 Villages 6 Islands cable links Shikinejima to other locations within Japan, reflecting the inter-island character of connectivity in the Izu archipelago region. This cable establishes a domestic corridor serving the island communities of the area rather than an intercontinental or international route.

Cables Landing at Shikinejima

The 5 Villages 6 Islands cable is the single submarine cable landing at Shikinejima. Spanning 355 kilometres in total length, it reached ready-for-service (RFS) status in 2019 and is noted as a draft system. All endpoints on this cable are located within Japan, confirming its role as a domestic inter-island cable. The cable's name itself reflects its purpose: providing submarine connectivity across a series of small island communities, of which Shikinejima is one.

Regional Context

Within Japan's submarine cable landscape, Shikinejima hosts a single cable, placing it among the smaller landing points in the country. Japan as a whole supports 51 submarine cables across 68 landing points, with major hubs such as Shima (12 cables), Maruyama (9 cables), and Chikura (8 cables) handling significantly higher cable volumes. Shikinejima's profile is closer to that of Hachijo and Minamiboso, each of which also serves a modest number of cables, suggesting a pattern of lighter-capacity inter-island landing points alongside Japan's larger international gateway terminals.

Network Role

Shikinejima functions as a single-cable terminus within Japan's domestic submarine cable graph. The 5 Villages 6 Islands cable connects the island to other Japanese communities, enabling telecommunications access for a remote island settlement that cannot rely on terrestrial infrastructure for its network connectivity. This type of landing point is distinct from Japan's international gateways: its role is entirely inward-facing, serving island communities rather than bridging continents.

In the broader context of Japan's 68 submarine cable landing points, Shikinejima represents the pattern by which smaller inhabited islands in the Izu chain secure their connectivity through purpose-built short-haul domestic cables, ensuring that geographic remoteness does not translate directly into network isolation.