Spanish Navy’s two newest submarines put to sea together

Spain’s first two S-80 Plus class submarines put to sea together for the first time this week, the Spanish Navy said.

The Isaac Peral (S-81) and the Narciso Monturiol (S-82) represent what the Navy described as another step in Spain’s strategic autonomy and its submarine force’s deterrent capability.

Isaac Peral, the lead boat of the class, was commissioned into the Spanish Navy in November 2023 after completing its own sea trials off Cartagena. Built by Spanish state shipbuilder Navantia, the submarine measures 80.8 meters (265 feet) in length with a hull diameter of 7.3 meters (24 feet) and a submerged displacement of about 3,000 tonnes.

Narciso Monturiol, the second submarine in the class, began sea trials in June 2026 following its first static dive that July near La Algameca Naval Base in Cartagena. That test evaluated the hull’s behavior and the flooding of its ballast tanks ahead of submerged navigation trials. The submarine remains in its testing program and has not yet been formally commissioned into the fleet.

Both submarines share the same core specifications and are named after 19th-century Spanish inventors credited with early submarine design work. The S-80 Plus program is intended to replace Spain’s aging Galerna-class submarines, in service since the 1980s, with a total of four boats planned. The third submarine in the class, Cosme García, remains under construction at Navantia’s Cartagena shipyard, where the vessel’s diesel engines were installed in July.

A defining feature of the S-80 Plus design is its BEST air-independent propulsion system, which uses fuel cell technology to generate electrical power at depth without surfacing, extending how long the submarines can remain submerged. The lead boats are entering service before the AIP system is fully integrated, with the technology expected to be added during future upgrades.

“The S80 programme is progressing in line with the agreed schedule, and the second submarine in the series will be delivered soon,” Navantia Chairman Ricardo Domínguez said in July, following the Narciso Monturiol’s first static dive. “Thanks to the close collaboration between the Ministry of Defence, the Spanish Navy and Navantia, the S80 programme is already making a significant contribution to the strategic autonomy of Spain’s submarine force and to the technological capabilities of our industrial ecosystem.”

The S-80 Plus program experienced years of delays after engineers identified buoyancy and weight distribution issues that required design changes before construction could proceed on schedule. Navantia has said the program supports more than 6,000 jobs across Spain’s defense industrial base.