Jalkapi XLUUV, India's Largest Unmanned Submarine With 20-Ton Weight and Upto 45-Day Endurance, Starts Taking Shape

India's push for self-reliance in defence technology has reached a new milestone with the development of the Jalkapi, an Extra-Large Unmanned Underwater Vehicle (XLUUV).

This ambitious project, currently under development, is poised to become the largest unmanned submarine in India's defence arsenal, significantly enhancing the Navy's underwater capabilities.

The initial design of the Jalkapi XLUUV was revealed at Aero India 2025, a major defence exhibition held in Bengaluru in February.

Developed by Hyderabad-based Rekise Marine Private Limited, the Jalkapi represents a significant step forward in India's indigenous defence innovation efforts.

This 20-ton unmanned submarine is designed to significantly improve underwater surveillance and strategic operations, particularly within the crucial Indian Ocean Region (IOR).

A scale model showcased at the Rekise Marine exhibit revealed the Jalkapi's sleek, cylindrical design, optimized for stealth and efficient movement through water.

The XLUUV is 11 meters long and is built to operate at depths of up to 300 meters. It is important to know that, the average depth of the Indian Ocean is 3,741 m. This operational depth makes the Jalkapi suitable for a range of missions.

Further, the submarine has impressive staying power, it is capable of operating autonomously for 30 to 45 days, a duration comparable to leading international models like Boeing's Orca XLUUV.

This extended endurance is achieved through a diesel generator that recharges the onboard lithium-ion batteries. The system allows the Jalkapi to surface, recharge, and resume its mission without requiring direct human intervention.

The Jalkapi's design incorporates specifications from the Indian Navy's Directorate of Naval Design (Submarine Design Group). It features a comprehensive array of sensors and instruments. This includes cameras for visual and infrared observation, multi-beam echo sounders for mapping the seabed, passive sonar to avoid obstacles, and sensors to measure water conductivity, temperature, and depth.

The Jalkapi's autonomous navigation is managed by a sophisticated system built on the ROS2/DDS framework, ensuring these various components work together seamlessly for fully autonomous, long-duration operations.

Rekise Marine was awarded the Jalkapi contract through the Innovations for Defence Excellence (iDEX) Aditi 1.0 initiative, a program launched by the Ministry of Defence in 2024 to foster innovation in the defence sector. This selection underscores the increasing contribution of India's private sector and smaller enterprises (MSMEs) to defence research and development.

Despite being a relatively small, robotics-focused company, Rekise Marine successfully competed against larger firms, showcasing its expertise in underwater automation and its close collaboration with the Indian Navy.

The Jalkapi's substantial size and payload capacity distinguish it from smaller autonomous underwater vehicles currently used by India. The 20 ton displacement capacity opens the possibility of different roles and uses for submarine.

Its 20-ton displacement allows for a wider range of potential applications, including supporting anti-submarine warfare efforts, conducting mine countermeasures, and performing electronic surveillance to detect enemy signals.

 

[Enforcer]

I am more eager to see additional Arihant class submarines in service. 8 would be the ideal number of subs in service so at any given time 6 are in service while 2 are being repaired/serviced.

 

[Somnath Sinhababu]

Govt should fast-track works on nuclear submarines...It will take 10 years to add the 1st nuclear attack submarine to induct into the Navy.. It's too much...Recently DRDO said they can build diesel-electric submarines within 5-6 years if the Govt gives approval...This is the golden opportunity...Grab it...Increase defence spending...

 

[Radha Ramanan]

Comparing this UAV to the Boeing UAV by the writer is just too much. Boeing is one of the largest defence companies with enormous tech power. That to a design on paper. We have to appreciate the team for the bold initiative and hope it achieves its goal. The hull design and the computer AI part of it can be done by them, but all other hardware must come from outside, be it engines, Li-ion battery, electricals, sonars, anechoic rubber tiles, periscope, data links, fiber optic gyro inertial systems, EW, etc. The general understanding is that designing a submarine is as hard as designing a fighter. This can also be converted to a platform to carry naval special forces. Let's not get carried away. We can rejoice when the prototype goes to sea.

 

[Anant]

I am more eager to see additional Arihant class submarines in service. 8 would be the ideal number of subs in service so at any given time 6 are in service while 2 are being repaired/serviced.

4-5 boats is sufficient. The Arihant-class is a decent design, but they are quite underarmed. It is better for us to move towards the S5-class instead.

 

[Frank]

This is just in design stage...

First make a prototype then this hype...

 

[Sandeep]

It's great that we are developing brand-new, unmanned submarines, but it's not clear what purpose or role these will play within the navy. Also, they haven't mentioned if they will be armed with torpedoes or lay mines.

 

[Leo red]

It should have the capability to send an air pipe and absorb air from above water. This will help to save energy for coming up and also avoid detection. Also, long-range, low-weight, autonomous kamikaze subs are more advantageous. Silent kill mode. Or, another option is that it should have mines or small kamikaze torpedoes or subs to attack other subs or ships without coming in contact. Kill enemies in deep waters without detection. Similarly, small but long-range autonomous subs can be dropped from cargo planes, so that they can go on silent or stealth missions.

 

[Hari Sud]

Chinese navy in Indian Ocean will be history, with this vessel around.

 

[beencensured]

This is just in design stage...

First make a prototype then this hype...

Yes, others see hype as an opportunity to counter, but private companies need hype to get funds and promote investments. So, there should be a balance. If you have invested in this company, you like to know of such achievements, like winning a contest.

 

[bonito]

Is it possible to launch this from surface ships for surveillance? So that the parent ship can stay at a safe distance?

 

[Frank]

Yes, others see hype as an opportunity to counter, but private companies need hype to get funds and promote investments. So, there should be a balance. If you have invested in this company, you like to know of such achievements, like winning a contest.

iDEX can give them crores of funds. No worries.