Reports suggest that Hanoi recently halted oil and gas drilling in Block 136-03 on Vanguard Bank in response to a Chinese threat of force against Vietnamese outposts in the area. That claim is impossible to verify, but the story highlights the vulnerability of Vietnam’s many smaller installations in and around the Spratly Islands. AMTI has previously examined Vietnam’s expansion of all but 2 of the 10 islets it occupies (Amboyna Cay and Namyit Island have seen no discernible reclamation work).
But the majority of the features Vietnam occupies are not rocks or islands; they are submerged reefs or banks on which Hanoi has built small, isolated structures. These facilities are difficult to defend or resupply, making them extremely vulnerable. Vietnam realizes this and has modestly expanded many of them since 2014, when relations with Beijing hit a historic low following a standoff over the deployment of a Chinese rig in disputed waters off the Paracels.
In many cases, Hanoi has constructed multiple facilities on a single reef or bank, leading to confusion about how many features it actually occupies. Vietnam has 49 or 51 outposts (it is unclear whether two artificial islands on Cornwallis South Reef damaged by a storm in late 2015 have been abandoned) spread across 27 features. The gallery below includes images of all of Vietnam’s outposts.
Vietnam’s outposts in the South China Sea fall into three categories: occupied islets, concrete buildings atop reefs (sometimes compared to “pillboxes”), and isolated platforms constructed on undersea banks. The latter are known as “economic, scientific, and technological service stations,” or Dịch vụ-Khoa (DK1). The Vietnamese government does not consider the six banks on which these structures are built to be part of the disputed Spratly Islands, but China and Taiwan do. They sit on the continental shelf that Vietnam claims from its coastline.
Scroll or use the buttons to zoom in/out, hover over features for names.
Hanoi built the DK1 structures in the late 1980s and 1990s in response to China’s occupation of six reefs in the Spratlys and declaration of oil and gas blocks overlapping with Vietnam’s at Vanguard Bank. Several of the original structures have been destroyed by storms, but 14 remain (along with one in the Gulf of Thailand). The standard blueprint for the DK1 facilities features a one- or two-story building on steel trusses housing a small garrison of troops. Some are topped with helipads and a few include a lighthouse. Since 2014, eight of these have seen the addition of a second, multi-story structure with a larger helipad connected to the original facility by a bridge.
The 24 pillbox-like fortifications that Vietnam has built on reefs throughout the Spratly Islands are only slightly less vulnerable than the DK1 platforms. These facilities each consist of between one and four separate concrete structures connected by bridges, often with jetties allowing small boats to dock. Like the DK1 platforms, these structures are difficult to defend and resupply. Many are accessible only by shallow-draft boats that can ride over the edge of the reefs, leaving them isolated even when they are within sight of other facilities on the same feature. In recent years, Vietnam has dredged channels through many of the reefs to allow larger vessels to reach the outposts. Since 2014, it has also expanded four of the facilities by adding additional buildings and bridges.
Complete list of Vietnam’s South China Sea facilities:
