Spanish shipbuilder Navantia has achieved a significant milestone by successfully installing its Hydrogen-based Air Independent Propulsion System (AIP) into an S-80 class submarine. This revolutionary system, named BEST (Bio-Ethanol Stealth Technology), marks the first deployment of a third-generation AIP in any submarine, showcasing Spain's naval engineering prowess. The event, held at Navantia's Cartagena shipyard and attended by Spanish National Armament Director Admiral Aniceto Rosique Nieto, celebrated the system's ability to enhance the Spanish Navy's submarine operational capabilities. The AIP technology allows submarines to stay submerged for extended periods by recharging their batteries underwater, eliminating the need for detectable snorkelling maneuvers and improving stealth. By using a bioethanol reforming process, the system generates Hydrogen on demand, combined with pure Oxygen to power a fuel cell silently and efficiently, setting it apart from other AIP systems globally. Navantia's AIP system not only boosts operational efficiency but also prioritizes safety and tactical flexibility, offering a cutting-edge solution in underwater propulsion. The company spokesperson highlighted Navantia's position as a leader in international submarine construction, emphasizing the advanced features of the AIP system that promote strategic autonomy and crew safety. Attendees at the event had the opportunity to inspect the AIP equipment housed in Section 3 of the S-83 Cosme García submarine, witnessing the meticulous construction procedures and safety protocols implemented by Navantia. This achievement underscores Navantia's commitment to excellence in naval innovation and sustainable military technologies.