Captain Philip Vian's signals trace the standoff outside Jøssingfjord. A Norwegian gunboat reported that Altmark had been examined at Bergen, carried no known prisoners, and was authorized to continue south, so Cossack temporarily withdrew beyond territorial waters. Britain had assembled four Tribal-class destroyers (Cossack, Maori, Sikh, and Nubian), the I-class destroyers Intrepid and Ivanhoe, and the cruiser Arethusa. Personnel from one of Arethusa's sisters reinforced the crews and boarding parties, leaving about forty-eight men ready to go aboard Altmark. The eventual seizure involved men crossing between ships on ropes, and recollections differ about whether some carried cutlasses. The signals and force list show that Britain treated the boarding as a prepared naval enforcement operation inside a diplomatic crisis.
Notable Point · 7:42-12:05
Signals and the Royal Navy force outside Jøssingfjord
Vian's signals reveal a substantial British interception and boarding force assembled outside Jøssingfjord while a Norwegian gunboat tried to enforce Altmark's authorized passage.