A tunnel thruster which is compact, quiet and can withstand the higher depth pressure encountered by a UUV. The UUV is usually a cylindrically shaped vessel and has a propulsor with control surfaces at one end. At two positions along the length of the body there are two cylindrical ports which pass through the body of the UUV. At each position one port is in the vertical plane while the other port is in the horizontal plane. These ports are four tunnel thrusters, which enable the maneuvering of the UUV. The tunnel thruster can be mounted in the ports of the UUV. The main components of the tunnel thruster includes a tunnel, motor assembly mounted in the tunnel, rotors on each end of the motor assembly and inlet ducts on each end of the tunnel. The tunnel thruster attempts to address the short comings of the commercial thrusters. The tunnel thruster is an all electrically powered thruster with all mechanical components contained within the tunnel. The rotors operate independently and are counter-rotating. Each rotor is directly driven by its own electric motor. The rotors are held in position by water lubricated fluid film journal and thrust bearings. The rotor duct assembly includes the rotor, inlet duct, bearing and seals, which can be used in other applications.