System Application

depth, or place on the bottom of the pool. Experiment with position/rotation of speaker until best pool coverage is obtained.

8.Remove the underwater speaker(s) from the water after each use, and store in dry cabinet. Do not leave the speakers in the water, as automatic pool cleaner will damage the cable. Avoid scraping the speaker, as damage to the coating will result in eventual failure. If speaker is stored for prolonged periods, a white film (plasticizer) may appear on the speaker or cage. This is normal -- film may be washed off using a sponge and warm soapy water.

These remarkable sets are a decade ahead of their time. Many engineers and scientists working in the field of underwater acoustics are still unaware of the feasibility of compressing the size of a low-frequency transducer without reducing it's efficiency; or of the feasibility of driving a piezoelectric transducer over broad-band frequencies using common transistor amplifier circuitry. A partial list of current uses follows:

Swimming & Scuba Instruction

Gunlap and false start signal, competitive swimming

Recall of scuba divers to excursion boat or habitat

Paging of scuba divers & swimmers at popular resorts

NASA training facilities

Military and scientific research

Interrogation of suspicious divers by law enforcement

Communication during filming of movies with underwater scenes

Coordinating underwater work parties

Coordinating underwater explorations

Coordinating underwater treasure hunts

Training of killer whales, dolphins, and other species

Repelling/attracting Beluga whales, sharks, dolphins, manatees, and other species, away from atomic test sites, hydroelectric facilities, fishing nets, oil/chemical spills, intercoastal waterways, and other potentially dangerous situations.