The S‑81 Isaac Peral is the first in Navantia’s S‑80 Plus class of submarines. It is equipped with an air-independent propulsion (AIP) system based on Bio-Ethanol Stealth Technology. With a length of 80 metres and a submerged displacement of nearly 3,000 tonnes, it offers great autonomy, stealth capabilities, and the ability to strike using guided missiles and torpedoes. It enhances the Spanish Navy’s submarine deterrence and power projection, as well as advanced covert special operations.