Ghost Fleet

The "Ghost Fleet" was a hypothetical Chinese stealth submarine program.

Background
In December 2075, the Defense Intelligence Agency's experimental Predictive Analytic Machine analyzed the superior capabilities of Chinese stealth technology and the ability of the Chinese to conceal large scale research projects from U.S. intelligence operatives and concluded that there was a 91% chance that China had conducted large-scale experiments with stealth technology. P.A.M. speculated that if China was indeed conducting such research, it may be related to the mysterious "Ghost Fleet" reported by two DIA stations in November. Accordingly, this could suggest that the Chinese had begun testing stealth submarine technology.

However, when asked to refine the answer and directly establish whether stealth submarines were in service with the Chinese navy, P.A.M. stated that the quality of the available data was too poor to arrive at any such conclusion. When asked to guess by a general, it promptly shut down.

P.A.M.'s speculation of the existence of large scale research into stealth technology was corroborated by an increase in the imports of stealth-related complex polymers and other key synthetic compounds to Shaanxi Province. However, both P.A.M. and the DIA general found the idea of stealth submarines far too dubious, with the general dismissing the idea of stealth subs as "nonsense" and saying that it was "ludicrous" that the U.S. "heard nothing." The matter was buried, with DIA personnel told not to ever mention the idea again unless they have concrete evidence of the fleet’s existence.

Appearances
The Ghost Fleet is mentioned in Fallout 4.