As part of Spain’s commitment to strengthening international cooperation and fulfilling its obligations with NATO, the Spanish Navy submarine Isaac Peral (S-81) will conduct its first international deployment during Operation Sea Guardian in the waters of the Mediterranean Sea. The vessel, belonging to the new S-80 Plus class, will remain deployed until the end of November, supporting maritime surveillance, counterterrorism, and the protection of NATO’s sea lines of communication.
The Isaac Peral recently departed from the Cartagena Submarine Base, where a farewell ceremony was held, presided over by Captain Alfonso Carrasco Santos, Commander of the Submarine Flotilla (COMSUBMAR). In his remarks, COMSUBMAR highlighted the professionalism and dedication of the crew, emphasizing the importance of this mission in consolidating Spain’s submarine presence and capabilities within the Allied framework. Under the command of Corvette Captain Fernando Clavijo Rey-Stolle, the submarine has a crew of 55 highly specialized sailors trained in the operation of its combat and propulsion systems.
Operation Sea Guardian is a flexible and ongoing NATO mission in the Mediterranean, focused on maritime security and counterterrorism. Since its launch in 2016, the Spanish Navy has played an active role in the operation, contributing to maritime domain awareness, the detection of illicit activities, and regional cooperation. The participation of the Isaac Peral further strengthens Spain’s role as a reliable ally fully integrated into NATO’s multinational operations.
The S-81 Isaac Peral is the first unit of the new generation of S-80 Plus submarines, a program developed by Navantia to replace the veteran Galerna-class (S-70) submarines. After overcoming various technical and financial challenges since its inception in 2003, the program reached a turning point with the delivery of the S-81 in November 2023, following an extensive redesign process that corrected buoyancy issues detected in the early stages.
The launch of the Isaac Peral, held in May 2021 in Cartagena, marked the beginning of a new era in Spanish submarine history. Over the past two years, the vessel has accumulated more than 5,500 nautical miles and 1,200 hours of sea trials, consolidating its operational capability and preparing its crew for long-duration missions. By mid-2025, the submarine achieved “high availability” status, becoming fully qualified for integration into international operations.
The S-80 Plus program includes a total of four conventional attack submarines: Isaac Peral (S-81), Narciso Monturiol (S-82), Cosme García (S-83), and Mateo García de los Reyes (S-84). Among these, the Isaac Peral was the first to enter service, while the S-82 Narciso Monturiol was recently launched on October 3, 2025, during a ceremony presided over by Minister of Defence Margarita Robles. This second submarine will soon begin port and sea trials, following the same process as its predecessor.
One of the program’s most notable features is the development of the third-generation AIP (Air Independent Propulsion) system, designed by Navantia, which will allow the submarines to remain submerged for up to three weeks without surfacing. This system will be installed for the first time on the S-83 Cosme García, while the Isaac Peral will integrate it from 2029 onwards, significantly enhancing its endurance and strategic capabilities.
With the deployment of the S-81 Isaac Peral in the Mediterranean, the Spanish Navy not only reinforces its commitment to international maritime security but also demonstrates the technological and operational maturity of the S-80 Plus program — a project that places Spain’s naval industry at the forefront of conventional submarine design and construction.
Image credits: Spanish Navy
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