This document provides information on various types of navigation instruments and systems used on ships. It describes gyrocompass, magnetic compass, sextant, radar, sonar, echo sounder, fish finder, Automatic Radar Plotting Aid (ARPA), Electronic Chart Display and Information System (ECDIS), Automatic Identification System (AIS), marine autopilot, rudder angle indicator, voyage data recorder, Global Positioning System (GPS), Electronic Chart Display (ECD), Marine VHF radio, public address system, log, speedometer, altimeter, Long Range Tracking and Identification (LRIT) system, Global Maritime Distress and Safety System (GMDSS), anemometer, barometer, and weather station.