The route of the British battlecruiser fleet took it through the patrol sector allocated to "U-32". After receiving the order to commence the operation, the U-boat moved to a position east of the Isle of May at dawn on 31 May. At 03:40, it sighted the cruisers and leaving the Forth at . It launched one torpedo at the leading cruiser at a range of , but its periscope jammed 'up', giving away the position of the submarine as it manoeuvred to fire a second. The lead cruiser turned away to dodge the torpedo, while the second turned towards the submarine, attempting to ram. "U-32" crash dived, and on raising its periscope at 04:10 saw two battlecruisers (the 2nd Battlecruiser Squadron) heading south-east. They were too far away to attack, but "Kapitänleutnant" von Spiegel reported the sighting of two battleships and two cruisers to Germany.