Rules for Allied and neutral merchant ships cruising off Gibraltar according to the Kriegsnachrichten of the Chef des Admiralstabes der Marine dated Berlin 14 August 1917

An item referred to submarine reconnaissance between end July-begin August steamships travelled west of Gibraltar between 250-270 degrees and according to a neutral captain to maximum 20 degrees west and then to the north. Usually was Gibraltar left in the evening nut also in the night going towards Gibraltar. Recently were in Gibraltar also convoys for the west assembled.

Source

Bundesarchiv RM-40-622