Submarines – Navantia

S81 Isaac Peral

The S‑81 Isaac Peral is the first submarine in Navantia’s S‑80 Plus class and features an air-independent propulsion (AIP) system based on Bio-Ethanol Stealth Technology. At 80 metres long and with a submerged displacement of nearly 3,000 tonnes, it offers long endurance, stealth and a guided-missile and torpedo strike capability. This strengthens the Spanish Navy’s submarine deterrence and power-projection capabilities and supports 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 ocean-going conventional 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 US company Lockheed Martin. It is unique among conventional submarines of its class in NATO and the EU in its ability to launch tactical land-attack missiles.