| Description: | A device which sends out a pulse of high-frequency sound and then reads returning echoes to give a range between the sounder and any obstruction. Low-cost models are usually effective to no more than 80 meters, and at ranges of over 40 meters they have litle accuracy. More sophisticated models (TL7+) are capable of showing a fiarly detailed display of the area at which they are aimed, including animal life and other details.
Echo sounders are usually mounted aboard boats and submersibles, where they serve as depth finders. Portable models, however, can be mounted in waterproof camera housings and used by divers. They not only determine depth, but also can be used to find horizontal ranges. |