The Una-class submarine was a class of six midget submarines built for the Yugoslav Navy at the Brodogradilište specijalnih objekata (Special objects shipyard) in Split during the 1980s. After the dissolution of Yugoslavia, ownership of the decommissioned boats passed on to Montenegro,which in turn offered them to the former Republics. Slovenia accepted and P-913 Zeta has been on display at the Pivka Park of Military History (Park Vojaške Zgodovine) since September 2011.