The present invention provides a self-propelled buoy for communication with an underwater object, the buoy comprising: a propulsion system for propelling the buoy an acoustic communication module configured to at least receive acoustic communications from a communication device associated with the underwater object and a propulsion controller that identifies, from the acoustic communications received by the acoustic communication module, position information for the communication device associated with the underwater object, wherein the propulsion controller outputs control information to control the propulsion system of the buoy to stay within a selected distance of the underwater object, and wherein the propulsion controller includes a course correction algorithm for making course corrections of the buoy which account for at least one of changes in underwater currents or in a movement of the underwater object, the course corrections enabling the buoy to stay within the selected distance of the underwater object.
