The S-80 Class are AIP (air independent propulsion) submarines currently under construction for the Spanish Navy. Four boats have been ordered, three of which are under construction by the Spanish company Navantia at its yard in Cartagena. The submarines are being fitted with a new propulsion system designed for a high degree of autonomy under water. Their mission includes: projection of naval power onto land, naval special warfare, surveillance, protection of naval forces and deterrence. The first was planned to enter service in the Spanish Navy in 2015, with a second in 2016, but a weight imbalance issue has been identified which is to delay the project between 12 and 24 months. The construction of the third in the series began in 2009. The Indian Navy is considering this submarine for i