OVERVIEW: The Maareech Advanced Torpedo Decoy System (ATDS) is an Indian towed torpedo defense system that detects, deceives, and diverts incoming acoustic-homing torpedoes. It provides a soft-kill countermeasure to protect surface warships.

DETAILS: Developed by DRDO’s NPOL (Naval Physical and Oceanographic Laboratory) and NSTL (Naval Science & Technological Laboratory) and produced by Bharat Electronics Limited (BEL), Maareech integrates hull-mounted and towed-array sonar with expendable and towed decoys. The system uses a hydraulically deployed towed array sonar and decoy, linked via fiber-optic cable to the onboard fire-control suite, for detection, classification, localization, and automatic deployment of countermeasures. The towed decoy emits acoustic noise in multiple countermeasure modes broadband jamming, echo repeater, and transponder to lure torpedoes away from the ship.

No variant codes beyond the base Maareech ATDS are publicly confirmed. Its unique multi-mode decoy and integrated sonar FCS configuration distinguish it from earlier, simpler towed lure systems.

FUNCTION: Upon torpedo detection by hull or towed sonar, the fire-control system computes threat parameters and automatically deploys the towed decoy via winch. The decoy then establishes a deceptive acoustic trail, drawing the torpedo off the ship’s hull and exhausting its seeker energy through misdirection.

NOTE:
IOC: 2015 (first production-grade systems inducted) 
Operators: India

SOURCE:
DRDO NPOL & NSTL; BEL ATDS Maareech System: https://bel-india.in/product/atds-maareech-system/ ; Defence Update – Maareech ATDS article: https://defenceupdate.in/maareech-atds-indias-indigenous-advanced-torpedo-defence-system/ ; Indian Defence News – Maareech anti-torpedo decoy inducted: https://www.indiandefensenews.in/2020/07/what-is-maareech-anti-torpedo-decoy.html ; The Hindu – Maareech flagged off: https://www.thehindu.com/news/national/kerala/maareech-indian-navys-advanced-torpedo-decoy-system-flagged-off/article68144929.ece