[5] Arriving off the Danish Lollard on 17 June and met Sperrbrecher IV, a type with a specially-armoured hull designed to set off mines and two torpedo boat escorts.

At the Kattegat Sperrbrecher IV departed and with two minesweepers, the ships entered the North Sea with an escort of a Dornier 18 flying boat and two fighter aircraft.

[6] Krüder headed for Jan Mayen, intending to wait for poor weather in the Denmark Strait before attempting to break out into the Atlantic for a rendezvous with U-A near the Cape Verde islands.

[6] On 31 July, near Ascension Island about 1,200 nmi (2,200 km; 1,400 mi) off west Africa, a ship was sighted at about 9:00 a.m. in clear weather.

each other The ship was the British 5,538 GRT SS Domingo de Larrinaga which turned away, transmitted an unknown attacker alert in Morse, "QQQQ" [– – • –] × 4, prepared the stern gun for action and raised the flag.

Krüder give chase, trying to jam the wireless calls from the ship and gradually overhauled it, opening fire at a range of 2 nmi (3.7 km; 2.3 mi).

Several hits on Domingo de Larrinaga started a fire near the bridge and killed four men; 32 members of the crew took to three lifeboats.

The pilot dropped a message purportedly from a British officer, that a German raider was in the area and ordered the ship to alter course and keep radio silence.

Pinguin exploded when the mines stored on board were hit and detonated; 332 members of the crew and about 200 of the prisoners were killed.