1. Sep. 1939: D. Poseidon south of Rio de Janeiro on her way from Hamburg to Punta Arenas. 

5. Sep. 1939: Chased by HMS Ajax and enter Mar del Plata to aviod capture.

Oct. 1939: Sailed from Mar del Plata for Germany via Denmark Strait to avoid the British naval blockade.

21. Oct. 1939: D Poseidon reports contact with two enemy merchant-cruisers (c) HMS Scotstoun and HMS Transylvania. She receives order to flee or destroy the ship. Signal to Norddeich: "DHTM 67⁰42'N 22⁰20'W von zwei Kriegsschiffen angehalten. Sind aufgefordret zu folgen. Nation englisch". 7 hours later: "Stoppen auf 67⁰08'N 21⁰18'W. Über Nacht keiner an bord. Schlecht Wetter".

22. Oct. 1939: Signal to Norddeich: "Sind aufgebracht bei Kap Nord Island" - 66⁰27'N 22⁰09'W. (x) - later: "Machen Boote klar - Prise kommt an Bord". The German crew attempted to scuttle their ship but this failed.

26.-27. Oct 1939: The damaged ship was taken in tow but sinks in bad weather on the 26th or 27th.

Daily Telegraph (3.11.1939): "Captured ships lifeboats found on Iceland Coast. It is reported from Reykjavik that the wrecks of two lifeboats marked with the name "Poseidon", have been washed ashore on the west coast of Iceland. The name "Poseidon" was painted over with the word "Hamburg". The "Poseidon", of 5864 tons, which belonged to Hamburg, was one of the ships mentioned by Mr. Chamberlain last week, when he gave names of a number of enemy vessels which had been captured by the Royal Navy. The discovery of the lifeboats is associated in Iceland with a number of shots were accompanied by columns of water rising the horizon".

Crew of both D. Poseidon and D. Gonzenheim arrived in Scotland in late October 1939. - Donaldson's School (?).

Crew of D Poseidon transferred to Internment camp 009 in Huyton, Liverpool - later send to camps in Canada. Kapitän Wilhelm Nielsen, was one of app. 87 sick merchant sailors who was repatriated from camps in Canada.