Ghost Fleet

The "Ghost Fleet" (name given by the DIA) was an alleged top secret Chinese naval unit.

Background
Before the Great War, Chinese stealth technology far outstripped the capabilities of the United States. There existed a high probability that testing had commenced in the form of Chinese submersibles known as the Ghost Fleet, as reported by A-31 and B-19 surveillance teams in November 2075.

Up until the end of 2075, American projects involving stealth technology were small scale, having only accomplished the reverse engineering of captured Hei Gui suits. Although no actionable intelligence had come out of the Shaanxi Province for over three years, the province had increased imports of complex polymers and other key synthetic compounds, the quantity of which was consistent with stealth technology research on a macro scale.

Appearances
The Ghost Fleet is mentioned only in Fallout 4.