British and French navies trying desperate to deal with German submarine warfare in second week of December 1939

An item reported that between 7-14 December British destroyers, escort vessels and anti submarine trawlers attacked 8 times German submarines and French patrols twice.

Source

The National Archives, Kew Gardens, England CAB-66-4-13 Weekly Résumé (No. 15) of the naval, military and air situation from 0700 7 December to 0700 14 December 1939.