Indian Navy's DSRV Tiger X Makes Historic First Deployment Outside Indian Ocean During Multinational Exercise XPR-25

The Indian Navy achieved a significant milestone in undersea operations by successfully deploying its Deep Submergence Rescue Vehicle (DSRV) Tiger X during the multinational submarine rescue exercise XPR-25, hosted by the Singapore Navy.

This marked the first time India's submarine rescue system operated beyond the Indian Ocean Region, conducting a full-spectrum rescue drill in the South China Sea where the Indian DSRV docked with allied submarines under simulated conditions.

XPR-25, conducted between September 15-25, gathered naval contingents from over 40 countries. The exercise was organized in two phases: a shore phase from September 15-20 and a sea phase from September 21-25.

During the sea phase, three submarine rescue units participated, each deployed on a dedicated mother ship: Singapore's MV Swift Rescue, Japan's JS Chiyoda, and India's newly commissioned INS Nistar. These vessels operated alongside submarines from the South Korean Navy, Japan Maritime Self-Defence Force, and Singapore Navy, which served as "disabled submarines" (DISSUBs) in the simulation.

The highlight occurred on September 23 when India's DSRV Tiger X performed its maiden dive in foreign waters. The mini-submersible successfully mated with South Korea's submarine Shin Dol-Seok (S-082) and subsequently docked with Singapore's submarine RSS Invincible, completing two successful rescue simulations.

India currently operates two DSRVs acquired from UK-based JFD Global under a 193 million pounds contract signed in 2016. Each system includes the rescue vehicle, launch and recovery equipment, Transfer Under Pressure (TUP) systems, and comprehensive logistics support with 25-year maintenance guarantees.

The TUP system plays a crucial role in deep-sea missions by enabling safe transfer of personnel between pressurized environments, such as from a rescue submarine to a hyperbaric chamber, while maintaining consistent pressure to prevent decompression sickness.

The exercise also featured the first operational deployment of INS Nistar, India's indigenously designed Diving Support Vessel (DSV), which was commissioned on July 18. This 118-metre-long vessel was constructed by Hindustan Shipyard Limited (HSL).

The order for two DSVs was placed in 2018, with delays resulting from the COVID-19 pandemic. Both vessels were launched in 2022, with Nistar officially delivered to the Navy on July 8. The ship has been assigned to the Eastern Naval Command in Visakhapatnam, which also manages India's nuclear-powered submarines.

With a displacement exceeding 10,000 tons, a beam of 23 metres, and an endurance surpassing 60 days, Nistar was specifically designed to support DSRV operations. It is equipped with a 15-tonne subsea crane, diving bell, ROVs, side-scan sonar, compression chambers, and a Self-Propelled Hyperbaric Life Boat. The vessel also features a front flight deck for helicopter operations.