The Altmark Incident
In February 1940, the German tanker Altmark was returning to Nazi Germany with 299 captured British merchant sailors on board. The sailors had been picked up from ships sunk by the Graf Spee. On its way to Nazi Germany, the Altmark exploited neutral Norwegian waters.
Officers from Norwegian vessels boarded the Altmark three times, but they conducted only cursory searches, taking the Germans' word that the vessel was on commercial business. In the hold, the prisoners were shouting and banging on the sides of the hull, but the Norwegians did not look below, and the Germans ran winches to cover the tumult. The Altmark was allowed to proceed.
But someone had passed the word to the Royal Navy. Captained by Philip Vian, HMS Cossack pursued the Altmark into Jøssingfjord. Norwegian naval forces tried to intervene then stood down.
Two hours before midnight on February 16th, a boarding party leaped on board the Altmark with bayonets. After hand-to-hand fighting they overwhelmed the ship's crew and German officers.
Down below in the hold, the British prisoners heard the shout, "Any Englishmen here?"
They shouted back, and heard, "Well, the Navy's here."