Aerial and satellite photos indicate that Chinese military construction efforts on Woody Island (one of the disputed Paracel Islands) are largely complete. The garrison consists of a battalion of naval infantry (not quite marines but close) and a 2,300 meter long air strip. This is long enough to support warplanes and commercial transports as large as Boeing 737s (which China has a lot of). A school building was completed in 2013 for the 40 children of officials and their families stationed there. There is an artificial harbor that can handle ships of up to 5,000 ton displacement. This harbor is heavily used because there is no local water supply and much of the water still has to be brought in along with fuel for all the vehicle (land, sea and air) as well as the generators. While there is some recreational fishing going on, the two thousand people on the island require regular food deliveries from the mainland.
In addition to the military garrison there is also a civilian rescue detachment equipped with helicopters and small boats. This detachment is largely for the waters around Woody Island and a few smaller islands that amount to about 13 square kilometers of land. That is expected to increase by 10-20 percent via dredging.
Construction continues on facilities for the capital of Sansha, a new Chinese municipality (city). Sansha is actually Woody Island and dozens of smaller bits of land (some of them shoals that are under water all the time) in the Paracels and the Spratly Islands to the south. In fact, the new "city" lays claim to two million square kilometers of open sea (57 percent of the South China Sea). China has said it has completed similar construction projects in the South China Sea but satellite photos reveal this to be untrue.
China claims the South China Sea and all islands (and near islands like reefs) as Chinese property. To reinforce these claims of sovereignty China is occupying uninhabitable islands and creating new ones by dredging sand from reefs and shoals to create new uninhabitable islands. Like Woody Island, these new islands will be staffed with troops and government employees and be supplied, at great expensive, from the mainland.