Ordered on 30 June 1922,[1] Ondine was laid down along with her sister ship Ariane[2] at Chantiers et Ateliers Augustin Normand in Le Havre, France, on 8 February 1923 with the hull number Q121.

[1] By 12 October 1928, the French Navy had 14 warships and two squadrons of seaplanes searching for any sign of Ondine or her crew along her entire planned route from Cherbourg to Bizerte.

[4] The French Ministry of the Navy continued to express confidence that Ondine would be found, taking the optimistic view that she merely had suffered a machinery breakdown of some kind that had crippled her propulsion and communications.

[11] Newspapers reported emotional scenes at Cherbourg and Rouen, France, where family members of the crew gathered for word of Ondine′s fate, and that Ondine′s commanding officer had had a premonition of disaster, writing to his parents before Ondine′s departure, "I embrace you for the last time.

[10] Ondine′s commanding officer was highly regarded in the French submarine force, and newspapers asked why on a clear, calm night Ondine′s crew did not see the approaching Ekaterina Goulandris in time to take evasive action and whether Ondine was using her running lights while operating on the surface in darkness.

[10] The press also questioned the decision to send Ondine on her cruise unescorted, because an escorting surface ship could have reduced the chances of a collision and responded quickly to any breakdown or emergency.