Submarines - Navantia

S81 Isaac Peral

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.

S-80 Programme: a state-of-the-art submarine, entirely designed and built in Spain Anaerobic propulsion AIP – BEST (Bio-Ethanol Stealth Technology)

This new-generation conventional ocean-going submarine is fully designed and built in Spain. One of its standout features is its third-generation anaerobic AIP system, known as BEST (Bio-Ethanol Stealth Technology). It includes a bioethanol reformer that produces hydrogen, which then reacts with oxygen in a fuel cell to generate electricity. This system extends its submerged endurance to up to three weeks, significantly reducing its detectability.

It is a highly automated submarine, and thanks to a state-of-the-art platform control system developed by Navantia Sistemas, it can be operated by a reduced crew (32 sailors plus 8 additional berths for embarked personnel).

It can reach submerged speeds in excess of 19 knots and dive to depths greater than 300 metres. The vessel is approximately 80 metres long, 7 metres in diameter, and has a submerged displacement of around 3,000 tonnes.

It is also equipped with a combat system developed by Navantia Sistemas in collaboration with the U.S. company Lockheed Martin. Uniquely among conventional submarines of its class within NATO and the EU, it is capable of launching tactical land-attack missiles.