"Delfin" was ordered in 1910 from the Toulon shipyards along with its sister ship, . It was delivered to the Royal Hellenic Navy just before the outbreak of the First Balkan War. Its first captain, Lt Cmdr Stefanos Paparrigopoulos, together with the 17-man crew, had been sent to France to receive their training, which, in the event, was cut short when the outbreak of the war became inevitable. The Navy Ministry ordered them to sail home, and "Delfin" sailed from France on 29 September, arriving in Corfu on the very outbreak of the war, 4 October. This unescorted, non-stop journey of 1,100 miles set a world record and confirmed the abilities of its crew, despite their limited training. However, it also meant that no reserve crew could be trained, limiting its battle effectiveness due to the crew's fatigue.