Sirius spent over 55 years sailing with cargo, regular passengers and tourists between Norway and Europe, and on the Norwegian coast.

Sirius was rebuilt twice, the final rebuild in 1927 converting her to a dedicated cargo ship, a role which she fulfilled for the rest of her existence.

[1] Sirius featured an overbuilt ("hurricane" or awning) deck, and was powered by a 700 indicated horsepower two-cylinder compound steam engine, propelling her at a speed of 10 knots (19 km/h; 12 mph).

The passenger accommodation was located at the main deck, while the cargo holds were situated afore and abaft of the engine room.

On one occasion in 1890, Sirius encountered the German royal yacht Hohenzollern I, carrying Emperor Wilhelm II on one of his cruises to Norway.

[2] In 1896, Sirius had electric lighting installed,[2] and in 1898 she stood in on the route from Bergen to Newcastle in England for ships undergoing maintenance.

Along with other ships in the still-unoccupied areas of Norway, Sirius was requisitioned by the Norwegian authorities to support the war effort against the Germans.

[6][13] Sirius was under instructions to use an outer route off the island of Senja, but due to misunderstandings was sailing close to the coast, where German bombers were regularly patrolling.

[19] In the late evening of 18 May, Sirius was spotted by a German bomber aircraft He 111 in the strait Solbergfjorden off Finnlandsnes on Dyrøya in Troms county.

[2][6][19] The first bomb hit the bow area, while the second struck amidships, breaking the ship in two lengthwise, in what was described by eyewitnesses on shore as "opening up like a book".

[2][19][20] Seven crew members, including both the captain and the first mate, were killed in the sinking, while 11 survivors were rescued from the water by local people in rowing boats.

[2][6][13][20] The survivors, who had been strafed in the water by the German aircraft, were later retrieved by the submarine tender Lyngen and the local steamer Mosken and brought to Harstad.