Capital ships can be difficult for a submarine to find and approach in open water. Their operational tasks still take them toward ports, coastal routes, and confined waters where an encounter becomes more likely. The debate turns on how much protection the ocean's size provides when a ship must operate near places that matter to the war. Barham's loss is initially described as a convoy operation, then corrected to exercises near Alexandria. A capital ship that stays far from contested objectives avoids some danger at the expense of its military effect.
Notable Point · 3:40:22-3:42:56
Why capital ships become exposed to submarines near operational objectives
Open-ocean interception is difficult, but operational requirements draw capital ships into approaches and confined waters where submarines can threaten them.