The German surface fleet maintained a threat alongside submarines and aircraft, forcing Britain to prepare for several kinds of attack at once. The Royal Navy therefore kept cruisers and destroyers on distant cover and retained battleships and fleet carriers for the possibility of a heavier sortie. Those forces had to be available whenever convoys sailed because Germany could choose when to come out. The deterrent effect of German surface ships consequently tied down British assets out of proportion to how often those ships actually fought.
Notable Point · 56:46-58:27
German surface ships mattered even when they stayed in port
The mixed threat of submarines, aircraft, and surface raiders forced Britain to retain cruisers, carriers, battleships, and destroyers for convoy cover.