Developed by the Brodarski Institute (BI) from Zagreb, the two strong class was built by the Brodogradilište specijalnih objekata (Special objects shipyard) in Split.

With the start of the Croatian War of Independence, both submarines were relocated to Boka Kotorska where they would be commissioned with the new FR Yugoslav Navy of, what would eventually become, Serbia and Montenegro.

[1] Both submarines, Sava (P-831) and Drava (P-832), were built by the Brodogradilište specijalnih objekata (Special objects shipyard) in Split, SR Croatia and named after rivers in SFR Yugoslavia.

Both Sava and Drava were part of the 88th Submarine Flotilla of the Yugoslav Navy, with the Lora Naval Base in Split being their homeport.

[5] With the start of the Croatian War of Independence both submarines were relocated to Montenegro where they were eventually commissioned with the FR Yugoslav Navy.

[10] A few days later Rajko Bulatović, commander of the Montenegrin Navy at the time, made a statement explaining the "Orca-2000" system was never installed on Sava, and was in fact, developed for a foreign customer.