He knew that the Germans preferred to attack at night, using daylight hours to shadow their prey. He knew that U-boat captains preferred to attack from the bow of the convoy, before falling back to fire torpedoes on the convoy’s beam, finally withdrawing to a safe distance to reload the tubes. He did not yet know, however, about the technique pioneered by Kretschmer, of attacking from within the perimeter of the convoy, at point-blank distance.
