Abstract: An imaging system for tracking the location and direction of movement of a first object comprises a plurality of marker devices adapted to be disposed in a pattern on the first object, a sensing device, and a processor. The sensing device is adapted to be disposed on a second object so as to view the marker devices, the sensing device being operative to detect the relative positions of the plurality of marker devices on the first object, and the processor is coupled to the sensing device to form an image of the relative positions of the plurality of marker devices and to determine the direction of movement of the first object.

Abstract: A method for diverting a sailing vessel is disclosed. A watercraft equipped with a harpoon having a hull-piercing head and a tail attached to a cable may swiftly approach the vessel in the aft position. Upon piercing the hull, an extraction-preventing means, such as spokes unfolded from the head, latching it in the hull and preventing the harpoon's withdrawal. Via a cable attached to the tail of the harpoon the watercraft may use low-speed high-traction propulsion means such as Voith-Schneider Propulsion (VSP) to pull and divert the vessel at the stern to a desired course. The watercraft may preferably have a combination of lifting hydrofoils with propellers and VSP propellers to provide the respective low-traction high-speed and high-traction low-speed modes of operation.