India is set to take a major step into deep-sea exploration early next year when two aquanauts from the National Institute of Ocean Technology (NIOT) pilot the Matsya-6000, a 28-tonne, indigenously developed manned submersible, to a depth of 500 metres off the Chennai coast. The dive marks the first stage of the Samudrayaan project under the Ministry of Earth Sciences, eventually aiming to send humans 6,000 metres below sea level.
NIOT scientists Ramesh Raju and Jatinder Pal Singh—India’s first aquanauts—will lead the mission. “This is the first time we will send humans to a depth of 6,000 metres, and safety is paramount,” NIOT Director Balaji Ramakrishnan told PTI.
Built After Technology Denials
Samudrayaan is also a testament to India’s push for Atmanirbhar Bharat, after repeated attempts to procure a foreign-made manned submersible failed due to technology restrictions. This prompted the government to develop its own deep-sea craft.
“We had the expertise to dive up to 1,000 metres. When we began exploring technologies across India, we realised DRDO, CSIR and ISRO labs already had much of what we needed,” Ramakrishnan said.
Why Human Missions Matter
While India has explored the ocean floor using remotely operated vehicles (ROVs), scientists say human presence dramatically enhances the scope for discovery.
“No camera can match the human eye,” said Sathia Narayanan, Project Director, Samudrayaan. “The perception humans bring will provide critical insights into the deep-sea environment.”
Only a handful of nations—including the US, Russia, China, Japan and France—currently have the technology for such deep exploration. With Samudrayaan, India is poised to join this elite group.
India’s Deep-Sea Ambition
The oceans hold vast untapped reserves of minerals, fuels and biodiversity. With an 11,098-km coastline, India has been pushing a “blue economy” policy to harness marine resources for economic growth.
Inside NIOT’s Chennai campus, the Matsya-6000 is taking shape. The submersible’s prototype uses a 2.25-metre boiler-steel sphere, housing Li-Po batteries, ballast tanks, emergency escape systems, propellers and buoys.
The first 500-metre dive is scheduled for early next year—roughly the operational depth of naval submarines. The mission will then progress toward a full 6,000-metre dive in 2027, coinciding with ISRO’s Gaganyaan human spaceflight timeline.
For the deep-sea phase, the current steel sphere will be replaced by a titanium personnel sphere, fabricated at ISRO’s Liquid Propulsion Systems Centre in Bengaluru. The facility has developed electron-beam welding capability to create the 80 mm thick pressure-resistant shell required to withstand 600 bar pressure at 6,000 metres.
Designed for Extreme Conditions
The Matsya-6000 is capable of descending at 30 metres per minute, equipped with portholes, high-intensity external lighting, robotic arms for sample collection and external cameras.
Every component is being certified by DNV, a global assurance and risk-management organisation. “The certification ensures it will be one of the safest vessels for deep-ocean exploration,” said Sethuraman Ramesh, Group Head, Deep Sea Technology, NIOT.
Learning from Global Experience
Earlier this year, both Indian aquanauts travelled to 5,000 metres onboard France’s Nautile submersible, gaining firsthand experience that is now guiding the development of Matsya-6000.
From technology self-reliance to deep-sea science, Samudrayaan represents a milestone moment for India—one that could redefine the country’s understanding and utilisation of its vast ocean resources.
