Navantia's shipyard in Cartagena has initiated the installation of an air-independent propulsion (AIP) system on the Spanish Navy's S-80 Plus-class submarine, the Cosme Garcia (S-83). This marks a significant upgrade as it is the first vessel in the class to integrate this advanced capability. The AIP system, which recharges the submarine's batteries using hydrogen produced from bioethanol, enables extended underwater operations, enhancing stealth and adaptability to various naval missions. The S-81 and S-82 submarines will also be retrofitted with this system during their respective overhauls. Despite initial design setbacks, the S-80 class submarines have seen improvements, with the redesigned vessels boasting increased dimensions, weight, endurance, and weapon deployment capabilities. The S-80 Plus-class submarine offers superior features such as extended endurance, higher surface and submerged speeds, torpedo tubes, and a greater crew complement, enhancing its effectiveness in naval operations.