Finnish terrain of deep impenetrable forests and long parallel glacial lakes forces Red Army onto the few roads, churned into frozen ruts by heavy tracked vehicles and clogged with horses, men and machines. This road strategy slows their advance everywhere and, worse, forces them into minefields and ranged killing zones in front of the Mannerheim line on the Isthmus. The Soviets grind forward days behind schedule, their hopes for blitzkrieg dashed. North of Lake Lagoda, Soviet 8th Army advances slowly with little resistance but comes in range of Finnish shore batteries at Taipale which pulverise them with higher firing rate and greater accuracy than mobile artillery.
U-36 is two days out of Wilhelmshaven (heading to the Kola Peninsula 25 miles from Mumansk to scout a proposed submarine base) when she is sighted on the surface by British submarine HMS Salmon near Stavanger, Norway. Salmon sinks U-36 with one torpedo (all 40 lives lost).