plural of SOFAR bomb

(nautical, military) A device (usually an imploding metal sphere or an explosive charge fuzed to explode at depth) which sinks in the ocean and creates a loud, low-frequency sound when it enters the sofar channel; used to determine the location of sunken vessels.

(hydrology, physics, nautical) The depth in the oceans, usually around 750 m below the surface, where the speed of sound is the lowest, causing it to transmit sound waves generated within this channel for long distances with little attenuation by acting as a waveguide.