Prior to World War II she completed seven long training cruises with trainees from the Yugoslav Naval Academy, including one to North America.

At the time that the Yugoslav Wars commenced in 1991, Jadran was undergoing a refit at Tivat in the Bay of Kotor, having been transferred from her home port of Split.

The only ship of this type in service with the Kingdom of Serbs, Croats and Slovenes was Vila Velebita, which belonged to the merchant fleet, and operated out of the Royal Nautical School at Bakar.

[4] Therefore, in 1925 the semi-official Yugoslav naval association, Jadranska straža (Adriatic Guard), launched an appeal for donations in order to purchase such a ship.

Despite the shortfall, the Ministry of the Army and Navy then allocated an initial sum of four million dinars for the planned sailing training ship.

[5] Jadran was ordered on 4 September 1930 from the H. C. Stülcken Sohn shipyard in Hamburg, Germany, based on plans drawn up by the naval engineer Josip Škarica.

[5] The Stülcken shipyard had not built a steel sailing ship since 1902,[4] but the navy had ordered four small tugs from it two years earlier and had been pleased with the vessels when they were delivered.

The ship had a Linke-Hoffmann-Busch 6-cylinder diesel engine for auxiliary propulsion which generated 380 bhp (280 kW) and under its power alone Jadran could achieve a top speed of 8.5–9 kn (15.7–16.7 km/h; 9.8–10.4 mph).

Other spaces included storage holds, washing and changing areas, toilets, offices, two galleys, a bakery, laundry, infirmary and attached sick room, and a brig.

Work proceeded apace, and she was launched on 25 June 1931, witnessed by the vice-president of Jadranska straža, Vice-Admiral Nikola Stanković, and was christened Jadran, the Serbo-Croatian word for the Adriatic Sea.

Financial issues arising from the Great Depression then impacted the construction, exacerbated by the fall in the value of the German Reichsmark, and the Hoover Moratorium, which released Germany from its obligations to pay World War I reparations owed to Yugoslavia.

Near Cape Finisterre on the Spanish coast, a wreath was placed in memory of all hands of SS Daksa, a Yugoslav merchant ship which had been lost there on 26 January 1930.

The event was attended by: the president of Jadranska straža, Dr Ivo Tartaglia, and many members of the association; Stanković, who was now the commander-in-chief of the navy; and several government ministers or their deputies, along with nearly all of the ships of the fleet.

She soon commenced a series of short training cruises along the Yugoslav coast between the northern Adriatic island of Susak and the port of Ulcinj in the south, to ensure that the trainees experienced the full range of weather conditions.

The second longer cruise of that year ran from 5 August to 5 October and visited Gibraltar, Lisbon in Portugal, Rabat and Casablanca in French Morocco, stopping in Málaga and Palma de Mallorca in Spain on the way home.

[6] From 10 June to 31 August, she conducted a training cruise to Malta, Villafranca Tirrena on the north-eastern tip of Sicily, Heraklion on the Greek island of Crete, Beirut in French Lebanon, Marmaris on the south-western coast of Turkey, through the Dardanelles to Istanbul, then through the Bosporus to the Romanian port of Constanța and the Bulgarian port of Varna, both on the Black Sea coast, before returning via Salonika and Piraeus in Greece.

Under Commander Jerko Kačić-Dimitri, Jadran first collected trainees from the petty officers' school at Šibenik before departing Gruž on 20 April.

She visited Malta, Lisbon, Cherbourg and Le Havre in France, Rotterdam in the Netherlands, Hamburg and Kiel in Germany, and Gdynia in Poland.

On the return leg, Jadran visited Stockholm in Sweden, Copenhagen in Denmark, and Oslo in Norway, before arriving in Portsmouth in the UK on 15 August.

Even though she was heavily loaded with provisions in the UK, rationing was soon imposed, and the crew ran out of meat and fresh vegetables well before she arrived home on 5 September.

[16] From its outbreak, Yugoslavia maintained a neutral position towards the war, so in 1940 and 1941 short training cruises could be conducted, but only within the Adriatic, mainly between Dubrovnik and Šibenik.

During her service as Marco Polo she featured prominently in an Italian naval propaganda film, Come Si Diventa Marinai (How to Become a Sailor) by Istituto Luce.

[6] After spare parts were made and additional equipment had been added,[21] in mid-1949 she was allocated – once again named Jadran – to a new home port of Divulje near Split, which had become the site of the Yugoslav Naval Academy in 1947.

A total of 26.95 tonnes (29.71 tons) of fuel meant that the ship's range on the engine alone increased to 4,730 nmi (8,760 km; 5,440 mi) at 7 kn (13 km/h; 8.1 mph).

In 1983, the ship celebrated the 50th anniversary of her commissioning,[20] and the following year she undertook her first Mediterranean cruise in two decades when she visited mainland Greece and the Greek island of Corfu in the Ionian Sea.

[25] At the time when the wars in Yugoslavia began in 1991, Jadran had been sent from her home port of Split to the Sava Kovačević Naval Shipyard in Tivat for a refit.

After the wars concluded, the new country of Croatia sought Jadran's return from rump Yugoslavia, which consisted of only the former Yugoslav republics of Serbia and Montenegro, Tivat being in the territory of the latter.

To mark her 70th anniversary in 2003, celebrations were held in August rather than September, in order to dissociate her from the late King Peter II of Yugoslavia, on whose birthday she had been officially "donated" to the Yugoslav navy.

[6] The following year, Jadran represented the state union at the 200th anniversary of the Battle of Trafalgar celebrations in Portsmouth, sailing through heavy weather in the Bay of Biscay en route.

[30] The previous month, the Croatian singer Vanna, who had been booked to perform on the ship as part of a celebration of the 85th anniversary of Jadran, cancelled her appearance due to pressure from Croatia.