At 01.01 hours on 23 Nov 1940 the Ootmarsum (Master J. de Vries) in convoy SC-11 was hit by one torpedo from U-100 from a distance of 600 metres and sank by the bow immediately. She sank so fast convoy commodore was not even aware that the ship had been sunk.
Type: Steam merchant Built: 1920 - A. Vuijk & Zonen, Capelle an der Ijssel Owner: Stoomvaart Mij Oostzee NV (Vinke & Co), Amsterdam
Tonnage: 3,628 tons
Haersolte, J.W.J. van (1947). Scheepsrampen in oorlogstijd, no. 5. J.F. Duwaer & Zonen, Amsterdam.