In January 1991, the
Cory Chouest and
Amy Chouest were used as part of the
Heard Island feasibility test, an experiment to transmit low frequency sound through the ocean from
Heard Island in the
Southern Indian Ocean as far as both ocean coasts of the US and Canada. The
Cory Chouest was chosen because of its central
moon pool and because it was already equipped with an array of low frequency transmitters. A
phase-modulated 57Hz signal was used. The experiment was successful and demonstrated that such sound waves could travel as far as the
antipodes. Planned transmissions had been for ten days, although owing to the bad weather conditions and the high failure rate of the transmitter elements, used at a frequency below their design frequency, the transmissions were terminated on the sixth day, when only two of the original ten transducers were still working. == Note==