The present invention is broadly directed to an unmanned surface vessel (USV) 10 broadly comprising: 1. a vessel body (12) adapted to contain a payload (14); 2. a front fin (16) and a rear fin (18) connected to and protruding from the vessel body (12); 3. a forward foil (20) and a rearward foil (22) connected to a distal end region of the respective front and rear fins (16) and (18); 4. propulsion means (24) operatively coupled to the rear fin (18) for propulsion of the fin (18) and the foil (22) through the water.

A propulsion system includes a duct and a fluid flow generator. The duct has an elongated cavity with an inlet portion and an outlet portion. The fluid flow generator is disposed in the duct. The fluid flow generator configured to receive a fluid to generate an inlet stream through the inlet portion and generate an outlet stream through the outlet portion. The outlet stream is configured to generate thrust for a vehicle on which the fluid flow generator and the duct are mounted, and at least one of the inlet portion or the outlet portion is bent in a circular shape to alter a direction of a corresponding either one of the input stream or the output stream.

Provided in some embodiments is a well torpedo system that includes a torpedo adapted to be advanced in a wellbore of a subterranean well. The torpedo including an integrated spool adapted to hold a fiber-optic (FO) umbilical including a FO line adapted to couple to a surface component, and an engine adapted to combust solid propellant to generate thrust to propel advancement of the torpedo in the wellbore.

Provided in some embodiments is a well torpedo system that includes a torpedo adapted to be advanced in a wellbore of a subterranean well. The torpedo including an integrated spool adapted to hold a fiber-optic (FO) umbilical including a FO line adapted to couple to a surface component, and an engine adapted to combust solid propellant to generate thrust to propel advancement of the torpedo in the wellbore.