Intelligence on U boat movements included material obtained from Enigma decrypts, although very few people who saw these weekly summaries were aware of that at the time:
More than thirty U-Boats have been operating during the week. A number of U-Boats have been reported north of the Belle Isle Straits and a large group which was situated in a wide area to the south-east of Greenland has now dispersed.
Another group, including two or three Italians, has been operating on the convoy route northwards from Gibraltar and others have been reported off Freetown, in the St. Helena area and in the approaches to the White Sea.
During the week ending the 29th October 886 ships, including 175 Allied and 24 neutral, were convoyed. Nine anti-aircraft ships, 113 destroyers (including 24 United States destroyers), and 117 sloops, corvettes and minesweepers were employed on escort duties.
Since the beginning of the war 86,687 ships have been convoyed, of which 451 have been lost by enemy action. During the month of September, 4,341 ships were convoyed, of which 36 were lost.
Imports into Great Britain by ships in convoy during the week ending the 25th October were 1,435,869 tons, compared with 789,286 tons during the previous seven days, and an average of 1,011,921 tons during the past ten weeks.
From the Naval Situation Report for the week as reported to the British War Cabinet, see TNA CAB 66/19/25