The second S-80-class submarine being built for the Spanish Navy is now afloat in Navantia’s shipyard in Cartagena as it prepares for the final stages of its construction and commissioning, including harbour and sea trials, Navantia reported on 17 November 2025.
Narciso Monturiol (S-82) “sits in the water after a long and delicate manoeuvre, carried out over several hours using a floating dock and involving a series of essential tasks and checks to ensure the operation was conducted safely, both inside and outside the submarine”, Navantia stated.
From now on, harbour trials will verify all systems, with key safety milestones such as fuel loading, battery charging and propulsion tests conducted while the boat is moored.
Once these trials are completed, sea trials, including navigation and diving tests, will begin, paving the way for delivery to the Spanish Navy.
The S-80 submarines have an overall length of 80.8 m, a diameter of 7.3 m and a submerged displacement of around 3,000 tonnes. They feature a combat and platform control system developed by Navantia’s Systems business unit and all boats in the class will ultimately have a revolutionary air-independent propulsion system, called BEST-AIP, that provides great stealth while submerged. The system allows the generation of electrical energy at any depth from fuel cells using technology derived from the aerospace sector. Thus, the S-80-class boats can remain submerged for weeks without surfacing to periscope depth.
However, first-in-class Isaac Peral (S-81), which was commissioned on 30 November 2023, and second-in-class Narciso Monturiol will not initially receive an AIP system but will have one retrofitted during their first major overhauls.
Navantia reported in November 2024 that the first installation of an AIP system into an S-80-class submarine – third-in-class Cosme Garcia (S-83) – had been completed.
Construction of the four S-80-class boats was authorised in 2003, with deliveries originally expected to begin around 2015, but excessive weight issues and a consequently required redesign caused significant delays. The redesigned class is now larger than when first conceived, with a length of 81 m instead of 71 m and a 3,000-tonne submerged displacement instead of 2,465 tonnes.
The submarines are armed with six 21-inch (533 mm) bow torpedo tubes and can carry heavyweight torpedoes, mines and Harpoon anti-ship missiles.
