The Indian Navy's INS Nistar, a Diving Support Vessel (DSV), recently spearheaded a multinational submarine rescue exercise in the South China Sea, marking a significant milestone in India's submarine rescue capabilities. The exercise, known as Exercise Pacific Reach 2025 (XPR-25), was hosted by the Republic of Singapore Navy (RSN) from September 15–25, 2025, and involved participation from over 40 nations.
INS Nistar, carrying the Indian Navy's Deep Submergence Rescue Vehicle (DSRV) Tiger X, played a central role in the sea phase of XPR-25. The exercise aimed to enhance coordination and interoperability among participating nations in submarine rescue operations. This included professional exchanges during a shore phase in Singapore and live rescue drills in the South China Sea.
A key achievement during XPR-25 was the Indian Navy's first-ever "mating" with foreign submarines. "Mating," in naval terms, refers to the successful linking of systems from two or more vessels to enable rescue or support operations. Over three days, the DSRV Tiger X achieved three successful matings with submarines from the Republic of Korea (ROK) Navy, specifically the Shin Dol-Seok (S-082), and the RSN's RSS Invincible. These operations simulated rescuing personnel from a disabled submarine (DISSUB). The Indian Navy's DSRV Tiger X also undertook its maiden dive outside the Indian Ocean Region during the exercise.
On September 25, 2025, the exercise culminated in a coordinated rescue drill led by the RSN, which was the first three-asset (R3) rescue in Pacific Reach history. INS Nistar spearheaded the operations by localizing and surveying the distressed submarine, RSS Invincible, and relaying critical information to MV Swift Rescue (Singapore) and JS Chiyoda (Japan). Subsequently, the Indian Navy's Remotely Operated Vehicle (ROV) and DSRV were deployed in rapid succession, achieving mating within one hour of the dive.
The Indian Navy's performance during XPR-25 has been lauded as a demonstration of its exceptional proficiency, technological capabilities, and commitment to international submarine safety. The successful completion of the exercise underscores India's readiness, interoperability, and contribution to regional safety and humanitarian response at sea.
INS Nistar, commissioned on July 18, 2025, is indigenously designed and serves as a mothership for DSRV operations. It is equipped with advanced features, including a 15-tonne subsea crane, diving bells, ROVs, and hyperbaric life support. The vessel's capabilities allow it to conduct deep-sea diving operations and facilitate complex underwater operations.
The Indian Navy inducted two state-of-the-art DSRVs between 2018 and 2019, one for each seaboard, which can conduct rescue missions at depths of up to 650 meters, placing India among a select group of countries with dedicated submarine rescue systems. Exercise Pacific Reach 2025 and the role of INS Nistar highlight India's growing capabilities and commitment to ensuring maritime safety and security in the region.
