Towed array sonar

[1] Trailing the hydrophones behind the vessel, on a cable that can be kilometers long, keeps the array's sensors away from the ship's own noise sources, greatly improving its signal-to-noise ratio, and hence the effectiveness of detecting and tracking faint contacts, such as quiet, low noise-emitting submarine threats, or seismic signals.

During World War I, a towed sonar array known as the "Electric Eel" was developed by Harvey Hayes, a U.S. Navy physicist.

U.S. Navy submarines typically store towed arrays inside an outboard tube, mounted along the vessel's hull, with an opening on the starboard tail.

[2] There is also equipment located in a ballast tank (free flood area) while the cabinet used to operate the system is inside the submarine.

[3] Hydrophones in a towed array system are placed at specific distances along the cable, the end elements far enough apart to gain a basic ability to triangulate on a sound source.

Long seismic streamers have intermediate paravanes along their length which can be used to adjust the depth of the array in real time.

[6][7] Towed array systems are also used by the oil and gas industry for seismic exploration of geological formations under the sea bed.

Effective use of the towed array system requires a vessel to maintain a straight, level course over a data sampling interval.