THE PENTAGON – As the Navy faces more complex threats to its manned ships from Russia and China, the service is moving quickly to field an unmanned “Ghost Fleet” — a new breed of armed unmanned surface combatants will add more sensors and weapons to the current fleet.

In Fiscal Year 2020, the Navy has budgeted $400 million for two of the proposed large unmanned surface vehicles in its research and development budget line. The Navy plans to continue buying two a year until FY 2024, for a total of about $2.7 billion.
https://news.usni.org/2019/03/13/nav...al-ghost-fleet