US ally’s newest submarine sinks a patrol ship with one torpedo strike in Atlantic drill

A submarine can deliver a devastating strike without ever revealing its position. Spain’s newest submarine, Isaac Peral (S-81), has demonstrated this capability by sinking a decommissioned patrol vessel with a single torpedo during a live-fire exercise in the Atlantic Ocean. This November 2026 engagement marks an important weapons demonstration for Spain’s S-80 submarine program, showing that its first operational boat can successfully engage a surface target while participating in a coordinated naval exercise. “Mastery of the underwater environment and control of the sea are essential tools for strengthening deterrence and ensuring maritime security,” Armada (the Spanish Navy) said in a post on X. However, sinking an unarmed, decommissioned vessel is different from defeating a modern warship equipped with detection systems, defensive weapons, and countermeasures. The exercise demonstrates successful weapon employment, not combat effectiveness against an actively defended adversary. How did the submarine sink its target? The engagement took place during SINKEX-26, a Spanish Navy exercise designed to evaluate weapons, crew readiness and coordination between naval, and aviation units. The target was Infanta Elena, a decommissioned offshore patrol vessel. Isaac Peral fired a single torpedo, successfully sinking the ship. The Navy announced the result on November 4, 2026, but did not disclose the exact engagement date, firing range, launch depth, or torpedo model. 📽️ Imágenes espectaculares del SINKEX26. Una demostración de precisión y capacidad operativa.⚓ El dominio del entorno submarino y el control del mar son herramientas esenciales para reforzar la disuasión y garantizar la seguridad marítima. pic.twitter.com/MQFo6X2kgQ— Armada (@Armada_esp) November 5, 2026 The exercise involved considerably more than the submarine. Participating forces included the frigates Cristóbal Colón and Navarra, the support vessel Carnota, the patrol vessel Relámpago, and a mine-countermeasures diving unit. Air participation included three AV-8B Harrier aircraft, a naval helicopter, a ScanEagle unmanned aircraft and a maritime patrol aircraft from Spain’s Air and Space Force. Captain Rafael Mira Calvo, commander of the 41st Escort Squadron, directed the operation from aboard Navarra. The combined exercise allowed the Navy to evaluate how different military units operate together. However, it has not explained whether other units supplied targeting information to Isaac Peral or how the participating aircraft supported the torpedo engagement. Environmental precautions were also part of the operation. Before the exercise, Infanta Elena underwent decontamination to remove fuels, oils, and potentially polluting materials. Authorities also assessed and monitored the exercise area to protect marine mammals and civilian navigation. Not the submarine’s first torpedo firing SINKEX-26 was not Isaac Peral’s first torpedo launch. The Spanish Navy had already documented torpedo launches during SINKEX-25, conducted on June 15–16, 2025, for crew training and weapons evaluation. Separately, Spanish broadcaster Cadena SER reported on June 25, 2025, that the submarine had completed its first torpedo launch carrying a live explosive charge. Other submarine torpedo-firing demonstrations have also highlighted the evolving capabilities of underwater weapons platforms. The Navy lists SeaHake Mod. 4 torpedoes among the submarine’s weapons, designed to engage surface ships and submarines. However, it has not confirmed whether this particular model was used in the latest sinking. What makes Isaac Peral important? Built by Spanish shipbuilder Navantia, Isaac Peral is the first of four conventional submarines planned under the S-80 program, a national defense project under which a new generation of submarines are being developed for the Spanish Navy Delivered to the Spanish Navy on November 30, 2023, it measures approximately 80.8 meters long and displaces around 3,000 tonnes underwater. It has six torpedo launchers and a core crew of 32. Its sister submarine Narciso Monturiol (S-82) has also entered sea trials. Its operational experience is also growing. In March 2026, the submarine completed a month-long Mediterranean deployment under NATO’s Noble Shield operation, spending more than 446 hours submerged and covering over 2,043 nautical miles. One major capability remains absent from its current configuration: the program’s planned BEST air-independent propulsion (AIP) system. Using hydrogen produced from bioethanol and oxygen, the fuel-cell technology generates electricity underwater, reducing the need to surface or snorkel to recharge batteries. Isaac Peral is expected to receive AIP during its first major overhaul. For Spain, SINKEX-26 adds a tangible weapons result to its newest submarine’s growing operational record. However, the exercise leaves a big question unanswered — how effectively would Isaac Peral perform against a modern warship actively searching for it and defending itself? Get the latest in engineering, tech, space & science - delivered daily to your inbox.Rupendra Brahambhatt is an experienced writer, researcher, journalist, and filmmaker. With a B.Sc (Hons.) in Science and PGJMC in Mass Communications, he has been actively working with some of the most innovative brands, news agencies, digital magazines, documentary filmmakers, and nonprofits from different parts of the globe. As an author, he works with a vision to bring forward the right information and encourage a constructive mindset among the masses.