Contains

• sonar

  A measuring instrument that sends out an acoustic pulse in water and measures distances in...

• compass

  Navigational instrument for finding directions.

• depth finder

  Navigational instrument used to measure the depth of a body of water (as by ultrasound...

• inclinometer

  An instrument showing the angle that an aircraft makes with the horizon.

• artificial horizon

  A navigational instrument based on a gyroscope; it artificially provides a simulated...