
In its original incarnation as C-tech, Nautel Sonar won a competitive procurement process to design, manufacture and validate Hull Mounted and Variable Depth sonar systems for the Visby Class Corvettes. These sophisticated systems were successfully handed over to the Royal Swedish Navy from 2002, with their operational tenure projected to extend well beyond 2040.
Nautel Sonar has fostered a decade-long collaboration with Saab Dynamics, the designated in-country service provider for the Visby systems. Over the lifespan of the product, Nautel Sonar has been actively engaged in offering Field Service Representative (FSR) assistance in Sweden, including comprehensive training for Saab’s technical personnel in maintenance practices for the sonar systems.
Furthermore, Nautel Sonar and Saab have joined forces to enhance the Sonar system software, working together on software upgrades. Presently, Nautel Sonar is deeply involved in the ongoing VISBY mid-life upgrade program, wherein the focus lies on reviving the existing sonar system components and furnishing novel replacement elements. This concerted effort is geared towards overcoming obsolescence challenges, thereby ensuring the continued operational efficacy of the sonar systems until the year 2040.

The Hull Mounted sonar systems of the CTS-36 variant, originally supplied in 1996 to the Royal Australian Navy’s Leeuwin/class Hydrographic Ships, continue to be operational.
The primary mission of these Hydrographic ships revolves around charting Australian waters, and the multi-purpose CTS-36 Hull Mounted Sonar (HMS) system has been specifically designed to offer obstacle detection capabilities ahead of the vessel. This is achieved by providing ample range for timely evasive maneuvers. The system boasts an impressive 30-year track record of effectively fulfilling this mission.
In 2015, a mid-life upgrade was conducted on the system to address obsolescence-related challenges. During this upgrade, the sonar was transformed into the CMAS-30D model, representing a modern enhancement.
One notable incident occurred during survey operations involving HMAS Melville, where the newly installed CMAS-30D sonar played a pivotal role in locating a crashed US Navy Osprey aircraft in Shoalwater Bay. This timely discovery resulted in the rescue of 23 sailors’ lives. Acknowledging their significant contribution to search and recovery efforts, the personnel of HMAS Melville were honored with the prestigious Meritorious Unit Commendation by the commanding officer of the US Marine Corps. This incident stands as a testament to the operational excellence of the CMAS-30D sonar.
Once again, Nautel Sonar has underscored its unwavering dedication to supporting its products throughout their active service life.