The Hunt for Red October (Jack Ryan, #3)

by Tom Clancy

The large-aperture towed array was at the end of a thousand-foot cable. Jones referred to the use of it as trolling for whales. In addition to being their most sensitive sonar rig, it protected the Dallas against intruders shadowing her. Ordinarily a submarine’s sonar will work in any direction except aft—an area called the cone of silence, or the baffles. The BQR-15 changed that. Jones had heard all sorts of things on it, subs and surface ships all the time, low-flying aircraft on occasion. Once, during an exercise off Florida, it had been the noise of diving pelicans that he could not figure out until the skipper had raised the periscope for a look. Then off Bermuda they had encountered mating humpbacks, and a very impressive noise that was. Jones had a personal copy of the tape of them for use on the beach; some women had found it interesting, in a kinky sort of way. He smiled to himself.