Her regular route was between Hamburg and Vancouver via the Panama Canal and the West Coast of the United States.

She then tried to reach Germany via the Norwegian Sea, but ran into the first day of the German invasion of Norway and was sunk.

Bremer Vulkan in Bremen launched her sister ship Portland on 19 April 1928 and completed her on 30 June.

Regular ports of call on the route were Bremen, Antwerp, Curaçao, Cristóbal, Los Angeles, San Francisco, and Tacoma.

Seattle was returning from Tacoma, San Francisco, and Los Angeles, so on 29 August she put in to Curaçao in the Netherlands Antilles.

At first she and a number of other German ships were in port in Willemstad, but then the Dutch authorities made them move 4 nautical miles (8 km) up the coast to St Michael's Bay.

On 28 March the armed merchant cruiser HMS Transylvania intercepted Mimi Horn in the Denmark Strait.

On the evening of 8 April Gyller instructed Seattle to anchor off the islet of Oksøy, off Kristiansand in the southernmost part of Norway.

[11] Large numbers of sea squirts, sponges, and cnidaria such as dead man's fingers have colonised it, along with fish and starfish.