Convoy SC 7

16–19 October 1940, Western Approaches, west of the Hebrides

German victory; 20 of 35 merchant ships sunk without loss

SC 7 was a slow convoy of 35 mostly elderly merchant ships from Sydney, Nova Scotia, with a single sloop as escort for most of the crossing. From 16 October 1940 a pack of U-boats, directed by radio from France, gathered on it west of the Hebrides. Two more sloops and two corvettes came out to meet it, but they had never worked together, had no radar and no plan, and kept dropping back to pick up survivors. On the night of 18–19 October the U-boats attacked on the surface and at night, slipping inside the convoy where the escorts' ASDIC could not find them. Otto Kretschmer in U-99 sank more ships than any other boat. Twenty of the 35 ships were sunk and two damaged, and no U-boat was lost. The next night the same boats fell on convoy HX 79. The two nights showed that escorts had to be trained to fight together as groups.