Walker and Roberts in anti-submarine warfare

Who was more influential in the Battle of the Atlantic: Johnnie Walker or Gilbert Roberts?

Both mattered: Walker provided a powerful operational model, while Roberts helped develop workable tactical solutions.

Walker and Roberts influenced anti-submarine warfare in different ways, which makes a simple ranking unhelpful. Captain Johnnie Walker supplied a visible operational example and a model other escort commanders could emulate. Captain Gilbert Roberts and the Western Approaches Tactical Unit turned analysis and wargaming into practical responses to the U-boat threat. One contribution helped sailors see what aggressive escort operations could accomplish, while the other improved the methods available across the wider system. Their effects were complementary rather than mutually exclusive.