She served in the Merchant Marine of Switzerland during the Second World War, notably rescuing survivors of several ships sunk by submarines.

In June 1941, she gave passage from Schiedam to New York City to the Dutch Resistance fighters Peter Tazelaar, Bram van der Stok and Erik Hazelhoff Roelfzema.

[5] On 25 March 1943, St. Cergue rescued survivors of the Swedish cargo Industria, sunk by U-518.

[6] In late September 1943, St. Cergue rescued the Portuguese steamer Mello, victim of an accidental fire, and managed to tow her to Recife.

[2] The 1977 film Soldier of Orange features St. Cergue, played by the French tanker Esso Port Jérôme, modified for the occasion.