The invention relates to an underwater work system 1 with at least one autonomous unmanned underwater vehicle 2 and one unmanned relay vehicle 4 floating at the surface of the water 3, which comprises a radio antenna 5 for external communication 26 and a drive 16. The underwater vehicle 2 is connected to the relay vehicle 4 via an internal communication device.The invention furthermore relates to a method for operating an underwater work system. In order to create an underwater work system with an autonomous underwater vehicle and an unmanned relay vehicle floating at the surface of the water as well as a method for operating such an underwater work system, which provides an increased efficiency of the autonomous underwater vehicle 2 with short mission times, it is provided according to the invention that the relay vehicle 4 is controllable by means of a control unit 16 via the at least one autonomous underwater vehicle 2 in due consideration of navigation information 17.