1. A faint echo sounded in the cave.

2. Multi-Beam Echo Sounder is an absolutely necessary seafloor mapping device with high accuracy and high efficient at 21st century. It is much fitted to sweep mapping for wide area.

3. Marine Equipment, Satellite Equipment, Gps, Radar, Echo Sounder Marine Equipment.

4. The simulated teaching experiment system of echo sounder by computer is put forward in this paper.

5. Inspection installation and water tightness transducer of echo sounder on berth.

6. Echo Sounder is a kind of acoustic measuring depth equipment, which can measure depth with the time between transmitted wave and echo on condition in which the speed of ultrasonic is fixed.

7. A device used underwater to produce pulses of sound, as for an echo sounder.

8. In bathymetric survey, the record seabed image is distorted due to the angular beam width of an echo sounder.

9. In bathymetric survey, the recorded seabed is distorted due to the beam - width of the echo sounder.