Sensor buoys were information gathering devices used in space and underwater. The space station Zirtran's Anchor employed a network of sensor buoys controlled by Defensus Solar as part of their early-warning system. Sensory buoys were also employed by Leviathan Submersible Carriers to track targets in orbit of a planet. The Leviathan would release the buoy underwater and it would float to the surface, activating at a designated time. The buoy would scan for targets in orbit and collect the data. The Leviathan would then retrieve the buoy and process the information.