Ocean observation and exploration with underwater vehicles are playing an increasingly important role in scientific research, environmental protection, resource exploitation, disaster prevention, and national security. As a platform expanding the application of the individual underwater vehicle, networks of unmanned underwater vehicles possess outstanding advantages and have become a hot spot and cutting-edge direction in underwater vehicle research and applications globally. This paper reviews the current progress of unmanned underwater vehicle networks both in China and abroad and analyzes several typical application examples. In addition, the most recent experimental results from the National Key Research and Development Program of China during the 13th Five-Year Plan period are highlighted, and the development direction of major technologies is discussed, which may provide a reference for optimizing technologies for unmanned underwater vehicles and expanding the network applications.