1891 built by the shipyard Samuel McKnight & Co. Ltd., Ayr (Scotland), Great Britain, as the steam yacht HELGA for Colonel Edward A. Gore, Derrymore, County Clare, Ireland (in those days part of the United Kingdom).
1900 bought by the Department of Agricultural & Technical Instruction for Ireland, Dublin, UK.
1908 sold to Richard A. Grech, London, and renamed CONSTANCE GRECH. The steamer was converted into a tug and rescue boat, and registered with the international call sign MLKN.
1912 sent to the Richard A. Grech enterprises branch in Istanbul, Ottoman Empire. The ship has been chartered by the Ottoman government and was used to transport ammunition and soldiers.
27.10.1912 discovered off the island of Lemnos, North Aegean, with a cargo of ammunition and 23 Ottoman soldiers aboard. Seized by the Royal Hellenic Navy and declared as a prize. [E][J]
1913 renamed TENEDOS and commissioned for the Royal Hellenic Navy. The steamer was in use as a lighthouse supply ship and later on as an auxiliary. [D][E][C]
28.10.1940 - 06.04.1941 during the Italo-Greek War she was active as a rescue boat. [B][C][D].
23.04.1941 attacked and sunk by German aircraft in Skaramagas Bay, Attica, Greece. Later declared as a prize by the German occupational forces and salvaged during summer 1941. [F][A][B][D][E]
15.10.1941 marked in the German “List of already salvaged ships” as being under repair. [K]
16.05.1942 under the command of Lt.z.S. Gero Kleiner in the 21. U-Jagdflottille as submarine chaser “UJ 2106”. Not in service. [H]
01.07.1942 in service (CO Lt.z.S. Gero Kleiner). [H]*
21.07.1942, 18:30 (German operational time), bombed by three 4-engined aircrafts in Souda Bay, Crete Island. No hits. [H]
04.08.1942 under the command of Lt.z.S. Beger (in lieu). [H]
07.08.1942, 07:33 (German operational time), while escorting a convoy consisting of the steamers PIER LUIGI, CAGLIARI, WACHTFELS and ELLI, was attacked with torpedoes by the British S/M HMS PROTEUS (CO Lt. Robert Love Alexander, RN) approximately 13 nm NW of Milos Island. WACHTFELS (8.465 grt) sunk due to a torpedo hit in position 36° 55´ N 24° 10´ E. [H]
01.10.-15.11.1942 under the command of Lt.z.S. Gero Kleiner. Not in service. [H]
16.11.1942 - 31.12.1943 unmanned and not in service due to repair works at Skaramagas. [H]
01.01.1944 in service under the command of Oberleutnant zur See (abbr. Ob.Ltn.z.S. = Lieutenant (Lt.)) Keller. [H]
16.05.1944 under the command of Ob.Ltn.z.S. Heise (in lieu). [H]
01.-19.06.1944 under the command of Lt.z.S. Johanson (in lieu). Not in service due to repair works. [H]
20.06.1944 left Piraeus together with the “Siebelfähre” (Siebel ferry) S.F. 284 and the motor sailer SYBILLE bound for Monemvasia and then Kalamata. [H]
21.06.1944, 17:00 (German operational time), torpedoed by the British S/M HMS UNSPARING (CO Lt. A.D. Piper RNR) 6 nm SE of Cape Maleas and sunk in position 36° 27´ N / 23° 14´ E. The first torpedo passed UJ 2106 five meters ahead, the second torpedo struck the bow and then the boat exploded and sunk immediately. S.F. 284 tried to rescue the survivors but she was also attacked and finally sunk with great losses. [N][H][I][L][M]
*) Gröner’s claiming, that the ship received the tactical sign 12 V 7, must be considered as faulty. [F]