gyroscopes; seismographs; tachometers; azimuth instruments; compasses for measuring; directional compasses; electric coils; electric sensors; electrical transducers; transducers; electronic sensors; electronic coils; Global Positioning Systems; Global Positioning System [GPS] navigation devices; magnetic coils; electromagnetic coils; marine depth finders; angle gauges; electric navigational instruments; navigational instruments; navigational apparatus for automobiles; optical sensors; photoelectric sensors; satellite-aided navigation systems; distance measuring apparatus; pressure measuring apparatus