Navy Large Unmanned Surface and Undersea Vehicles: Background and Issues for Congress [Updated July 15, 2021] [open pdf - 2MB]
From the Introduction: "This report provides background information and potential issues for Congress for three types of large unmanned vehicles (UVs) that the Navy wants to develop and procure in FY2022 and beyond:  Large Unmanned Surface Vehicles (LUSVs);  Medium Unmanned Surface Vehicles (MUSVs); and  Extra-large Unmanned Undersea Vehicles (XLUUVs). The Navy wants to acquire these large UVs as part of an effort to shift the Navy to a new fleet architecture (i.e., a new combination of ships and other platforms) that is more widely distributed than the Navy's current fleet architecture. The Navy's proposed FY2022 budget requests $434.1 million in research and development funding for these large UVs and their enabling technologies."
CRS Report for Congress, R45757
Congressional Research Service: https://crsreports.congress.gov/