A method and apparatus for distributing satellite navigation data is described. Disclosed methods and devices can also be utilized to form nano- and micron-sized depressions in a substrate according to a more economical process than as has been utilized in the past. The therapeutic silicone composition of the present invention contains a silicone gel formulated with inert thickening agents andor carriers sufficient to provide a firm, semisolid silicone gel material that substantially retains its shape when extruded from a tube. By controlling steering, drive and braking systems of the follower vehicle with a servo-actuator, the follower vehicle is guided toward the waypoint by minimizing the difference between the first and second sets of GPS coordinates. Water movement deflects the exterior portion of the arm, which pivots around the seal, closes the connection to the power source, and causes the illumination source to produce light.