The Navy Capability Fewer Than Ten Countries Actually Have

Here's What Actually Happens When a Submarine Gets Stuck If a

submarine becomes disabled on the seabed, its crew has hours, not days, before oxygen and pressure become fatal. Getting them out requires two separate things working together: a small rescue vehicle that can dock onto the submarine's escape hatch underwater and transfer crew out in pressurized safety and a mother ship large enough to carry that rescue vehicle to the exact location, deploy it precisely and support divers who may need to work at extreme depth for hours or days at a time.

INS Nipun is that second piece - and until now, that second piece was the part of the chain India was weakest on.

The Part That's Actually Hard: Saturation Diving

The headline technology here is "saturation diving," and it's worth actually explaining rather than just naming. Normally, a diver who goes deep has to decompress slowly on the way back up, because their body absorbs dissolved gas under pressure that needs to be released gradually - go too fast and you get decompression sickness.

Saturation diving solves this differently: divers live inside a pressurized chamber on the ship for days at a stretch, staying at working pressure the whole time and only decompress once, at the very end of the mission, instead of after every single dive.

That's what makes sustained, complex underwater work - like reaching a stranded submarine and working around it for an extended rescue operation - actually feasible instead of impossibly slow.

Where India Now Stands Before

Nistar-class vessels, India had DSRVs (Deep Submergence Rescue Vehicles, acquired to allow India to attempt independent submarine rescue rather than depend on foreign navies) but lacked a purpose-built mother ship optimised to deploy and support them with saturation-diving capability at scale.

INS Nipun closes that specific gap. Very few navies globally - the US, UK and a small handful of others - maintain a genuinely integrated submarine-rescue chain of this kind. That scarcity is exactly why Admiral Swaminathan's framing of India as a potential "preferred submarine rescue partner" isn't overstatement: a capability this rare converts naturally into maritime diplomacy, since any regional navy operating submarines has a direct interest in knowing who nearby can actually help if something goes wrong.

For the exam, the real insight isn't "India commissioned a new naval ship"

• it's that the difference between having a rescue vehicle and having a genuine rescue capability lies entirely in the unglamorous mother-ship infrastructure that gets that vehicle to the right place, at the right pressure, in time - and that infrastructure gap, not vehicle technology, is usually where naval capability claims quietly fall short of naval capability reality.