The images collected by the Federation of American Scientists (FAS) in February 2008 shows that China constructed a large scale underground base for its naval forces.

[5] In August 2020, satellite imagery from Planet Labs appeared to show a Shang-class submarine entering the underground base.

The US Department of Defense estimated that China would have five Type 094 nuclear submarines operational by 2010 with each capable of carrying 12 JL-2 intercontinental ballistic missiles.

It is 150 nautical miles (280 km) to the closest of the disputed Paracel Islands or the city of Da Nang, Vietnam.

[7] The submarine base is only a few miles from the city of Sanya, a popular tourist destination and the site of a major planned cruise hub.