Thales logs 100th order for CAPTAS towed sonar

Thales announced the receipt of the 100th order for its Combined Active-Passive Towed Array Sonar (CAPTAS) system on October 2. The announcement seems to underscore the importance of anti-submarine warfare capabilities.

The CAPTAS system, which has been in continuous development for over 30 years, functions as a Variable Depth Sonar (VDS) solution. The system is engineered to provide long-range underwater detection, a capability described by the company as critical for navies seeking to establish and maintain a tactical advantage against sub-surface threats in challenging acoustic environments.

Thales reports that the CAPTAS family of systems is now in service or on order with 17 navies globally, fitted to 17 different platform types. The equipped vessels range from smaller platforms under 1,000 tonnes to larger frigate and destroyer-type combatants.

Original development of the system was conducted in partnership with the British, French, and Italian navies. Current known users of the system include the Royal Navy with the Sonar 2087 variant on Type 23 and Type 26 frigates, the French Navy on their FREMM and FDI frigates, the Italian Navy on their FREMM frigates, and the US Navy for its new Constellation-class frigates (FFG-62). Other known operators of CAPTAS-family variants include the navies of Egypt, Saudi Arabia, Malaysia, Mexico, Norway, Poland, the United Arab Emirates, Chile, and Ireland.

Sébastien Guérémy, Vice-President of Underwater Warfare activities at Thales, stated that the company’s understanding of the requirements of more than 50 navies worldwide has made the CAPTAS system an essential choice for contemporary and future anti-submarine missions.

Tech profile: CAPTAS

The CAPTAS family constitutes a Variable Depth Sonar (VDS) system engineered for long-range Anti-Submarine Warfare (ASW), classification, and tracking. Deployed from a surface vessel using a specialised handling system. The core technological advantage of CAPTAS lies in its VDS capability, which allows the towed body to be positioned at optimal depths. This flexibility is essential for overcoming acoustic propagation challenges in deep, shallow, and littoral waters.

Operationally, the system provides omnidirectional 360° active and passive surveillance across long ranges. This functionality is achieved through a bi-static configuration that integrates a low-frequency active transmitter, typically using free-flooded ring transducers, with a towed passive linear array. This combination allows the system to transmit acoustic pulses while simultaneously receiving both ambient underwater noise and echo returns, significantly enhancing detection performance. The CAPTAS family is scalable to suit various vessel types, encompassing the compact CAPTAS-1 for smaller corvettes, the CAPTAS-2 (UMS 4229) for medium-sized frigates, and the high-end CAPTAS-4 (UMS 4249 or UK’s Sonar 2087) for large frigates and destroyers.

Calibre comment

ASW has come to rely on passive sonar, which does not emit any signals to detect submarines but relies on its ability to pick up the signals made by submarines. However, current Russian submarines like the Yasen-class are so quiet that there is a growing movement towards active sonar. Other companies like SEA and Zero USV are positioning thin towed-array sonars, which can be deployed from uncrewed vessels to expand the size of the sensor network and support larger systems like CAPTAS.  

By Sam Cranny-Evans, published on October 3, 2025. The lead image shows the CAPTAS deployment mechanism at the rear of a ship. Credit: Thales.