The Thelma, a steel hulled steamship, laden with coal and other general cargo, one boiler, 133hp, 65.71 L x 9.77 B x 4.67 D metres, 1002 gross tons, built 1903 A. Vuijk. Capelle a/d Ysel (Capelle aan den IJssel, The Netherlands??), Owner Scandinavian Shipping Co. Ltd. Captain R. Tait, seventeen crew, registered in Glasgow, Scotland, and in passage from Glasgow, Scotland to Gothenburg, Sweden.
At 2.30pm on September 26th 1916 the German submarine U-20, Captain Walther Schwieger, was sighted two miles astern of the Thelma, it proceeded to fire on the Thelma with its deck gun, scoring two hits. It then closed in to a distance of one mile, and by the time a fourth shell had been fired the Captain of the Thelma gave the order to stop the vessel and for the crew to abandon ship. When they had only pulled away a short distance in the ship's boat, U-20 closed in and fired one torpedo at the Thelma from very close range, causing her to sink at 3.05pm at a position approx 24 miles E of Fair Isle.
U-20 then came alongside the small boat, and transferred all seventeen crewmembers on to her deck, she then steamed SE for two hours before transferring them on to the Danish schooner Marie. The Marie in turn transferred them on to the Royal Navy vessel HMS Mischief at 9am the next day, who subsequently landed them safely at Thurso, Scotland. The Captain of the Thelma was able to destroy the ship's confidential papers before abandoning her.