Indian Submarine fleet operates about 19 submarines in 2025, bringing together nuclear-powered ballistic missile submarines and diesel-electric attack boats. You’ll find homegrown Arihant-class nuclear subs alongside French-designed Kalvari-class Scorpenes in this diverse underwater fleet, with exciting expansion plans through Project 75I and additional Scorpene programs on the horizon.
The Indian Navy hit a major milestone this past January when they welcomed INS Vaghsheer into service, wrapping up the initial Project-75 Scorpene series. While this marks real progress toward building submarines at home, the Navy still wrestles with aging boats and is pushing hard to modernize and grow the fleet by 2035.
Numbers in Indian Submarine fleet
I have listed Missile capacity and their range of Indian submarine fleet. The current stats looks impressive compared to Pakistan but still we need advancement in Nuclear powered subs.
🔹 Conventional Diesel-Electric Submarines (SSKs)
- Kalvari Class (Scorpène Class) – 6 subs
- Missiles: Exocet SM39 (Range 50–70 km), future BrahMos (450–600 km, under integration)
- Sindhughosh Class (Kilo Class) – 7 subs
- Missiles: Klub-S / 3M-54E (Range 220–300 km), some upgraded for BrahMos (~450–600 km)
- Shishumar Class (Type 209) – 4 subs
- Missiles: Primarily torpedo-armed, planned Harpoon (124 km)
🔹 Nuclear-Powered Ballistic Missile Submarines (SSBNs)
- INS Arihant (Arihant Class) – 1 sub (in service)
- Missiles: K-15 Sagarika (750 km), K-4 SLBM (3,500 km, trials) – 12 tubes for K-15 / 4 for K-4
- INS Arighat (Arihant Class) – 1 sub (commissioning soon)
- Missiles: Same as Arihant – K-15 (750 km), K-4 (3,500 km)
- INS Aridhaman (Arihant Class, under construction) – 1 sub
- Missiles: 8 tubes for K-4 (3,500 km)
- Future S5 Class SSBNs (planned, larger) – 3 subs
- Missiles: 12–16 tubes, K-5 (~5,000 km) & K-6 (~6,000 km, MIRVs)
🔹 Nuclear-Powered Attack Submarines (SSNs)
- INS Chakra (Akula Class, leased) – 1 sub (returned in 2021, replacement expected)
- Missiles: Klub cruise missiles (~300 km), torpedoes
- Indigenous SSN Program (6 planned) – under development
- Missiles: Expected BrahMos (450–600 km) and future long-range cruise missiles
What Does Indian Submarine Fleet Look Like Today?
Right now, India’s underwater force includes around 19 operational submarines – that’s 17 diesel-electric attack subs and 2 nuclear ballistic missile boats. Don’t expect this number to stay exactly the same month to month though, since maintenance schedules and refits constantly shuffle which boats are available for action. Each class of submarine brings something different to the table, playing unique strategic roles.
Nuclear Submarines – The Heavy Hitters
India’s nuclear deterrence rests squarely on the Arihant-class SSBNs – these are the submarines that give India its crucial second-strike nuclear capability. Think of them as the ultimate insurance policy. The first boat, INS Arihant, changed everything when it joined the fleet in 2016. Then came INS Arighaat in 2024, added more indigenous technology and better stealth features to Indian submarine fleet.
The next one which is joining Indian submarine fleet is INS Aridhaman, currently going through sea trials and expected to join soon. This one’s bigger and badder – it can carry eight missile tubes loaded with long-range K-5 ballistic missiles that can reach targets 6,000 km away. These nuclear subs carry different missile types like the K-15 and K-4 variants, ensuring India can strike back even if someone hits first.
Looking ahead, India’s working on even more impressive S5-class SSBNs that’ll be massive – we’re talking boats that can carry up to 16 submarine-launched ballistic missiles. There are also plans for include nuclear-powered attack submarines to Indian submarine fleet around 2036.
Conventional Diesel-Electric Submarines – The Workhorses
Indian submarine fleet have following conventional deiseal powered subs , Divided into three main groups:
Kalvari-class submarines represent the most modern boats in the fleet. Six of these French-designed, Indian-built submarines joined the Navy between 2017 and 2025. At 1,775 tonnes each, they’re built with modular construction that makes future upgrades easier – including adding Air Independent Propulsion systems that’ll let them stay underwater much longer.
The Sindhughosh-class boats came from Russia, and seven are still in service, though many are getting long in the tooth. These older submarines have gotten missile system upgrades and new sensors to keep them relevant, but they’re slowly being phased out.
Then there are four Shishumar-class submarines – German-built boats that are going through major life-extension work to keep them active through the 2030s.
Recent Wins and Milestones
January 2025 was a big month when INS Vaghsheer officially joined the Indian submarine fleet, completing nearly two decades of submarine building at Mazagon Dock Shipbuilders Limited. This boat closed out the original Kalvari program – a real achievement for indigenous shipbuilding.
Just before that, at the end of 2024, an important contract got signed allowing engineers to retrofit Air Independent Propulsion technology onto the lead Kalvari submarine. This upgrade will make it much stealthier and able to stay submerged longer.
The Navy also doubled its nuclear submarine strength in 2024 when INS Arighaat became operational. Right now, more than 55 ships and submarines are under construction across Indian shipyards – showing just how quickly the fleet is expanding.
What’s Coming Next – Project 75I and More Scorpenes
Project 75I is India’s most ambitious submarine plan yet – six cutting-edge diesel-electric submarines with Air Independent Propulsion systems. After lots of delays, it looks like Mazagon Dock Shipbuilders working with German company ThyssenKrupp Marine Systems will build these boats, though contract talks are still ongoing.
These new submarines will pack vertical launch systems for land-attack cruise missiles, enhanced stealth capabilities, and much better underwater endurance to Indian submarine fleet. The first one should enter service in the early 2030s.
At the same time, there are plans for three more Scorpene submarines with lots of Indian-made systems, serving as a bridge while Project 75I gets rolling.
The 2035 Vision – Going Big
India has set some serious goals for 2035 – more than 200 warships and submarines total. That would mean 28 or more submarines, including everything currently in service plus all the new boats from Project 75I, additional Scorpenes, and new nuclear submarines. This isn’t just wishful thinking – it’s directly addressing the challenge from China’s growing submarine fleet and Pakistan’s modernizing underwater capabilities.
The budget numbers are huge, and with submarines taking 7-8 years to build, contracts need approval soon to hit these targets. Everything emphasizes building in India through “Make in India” policies, gradually reducing dependence on foreign suppliers and making Indian submarine fleet strong.
What These Submarines Can Do
Modern Indian submarine fleet have pretty impressive machines. The Kalvari-class boats feature advanced stealth coatings, sophisticated sonar systems, and weapon tubes that can launch 18 different types of torpedoes and missiles. Once they get their AIP retrofits, they’ll be able to stay submerged for weeks instead of having to snorkel every couple of days.
The Arihant-class nuclear submarines ensure India maintains credible nuclear deterrence by staying hidden underwater with ballistic missiles ready to launch if needed. These boats can disappear for extended periods, making them nearly impossible to track and destroy.
Future Project 75I submarines will bring land-attack missile capabilities to conventional submarine warfare, giving India much more precision strike capability and operational flexibility underwater.
Common Questions About India’s Submarine Fleet
How many submarines does India actually have? About 19 total – 17 diesel-electric attack submarines and 2 nuclear ballistic missile submarines.
Which submarine is the newest? latest addition to Indian submarine fleet is INS Vaghsheer, commissioned on January 15, 2025.
What exactly is Project 75I? It’s the next-generation submarine program that’ll build six AIP-equipped diesel-electric submarines through a partnership between ThyssenKrupp Marine Systems and Mazagon Dock Shipbuilders.
What nuclear submarines does India operate? The Arihant-class SSBNs form the backbone of India’s sea-based nuclear deterrent.
When will new submarines join the Navy? The third Arihant-class boat should arrive in 2025, while Project 75I submarines are planned for the early 2030s.
This growing submarine fleet really shows India’s push toward maritime independence, better underwater warfare capabilities, and solid strategic deterrence for the decades ahead. It’s an exciting time for Indian naval power, with modern technology meeting ambitious expansion plans.