This lecture overviews Autonomous Underwater Vessel Perception that has many applications in Autonomous Underwater Vessel missions. It covers the following topics in detail: Hydroacoustics, Acoustic Beacons and Modems, Acoustic Doppler Current Profiler (ADCP), Doppler Velocity Log (DVL), Sonar, Imaging, Ranging / Bathymetric, Optical Sensors, Led Beacons, Gated viewing.