The fjord's narrow geometry shaped the decisions that followed aerial contact. HMS Arethusa, HMS Intrepid, and HMS Ivanhoe reached Altmark before Vian's Tribal-class group. The I-class destroyers chased her into the fjord, where Norwegian torpedo boats drove them off because Britain wanted to avoid a fight with Norway. Altmark later attempted to strike Cossack in the confined inner section. The pursuing ships were uncertain enough about the channel depth to ask a local sixteen-year-old whether it was safe. Their willingness to proceed depended partly on local knowledge that their own pilots lacked.
Chapter · 46:28-51:56
How confined fjord waters shaped the interception
Maps, narrow channels, uncertain depth, and Norwegian torpedo boats explain why the first British interception drove Altmark deeper into the fjord instead of ending the chase.