It's ok because I believe that you are patroling along the British eastern coast. Ant it's the beginning of the war. Destroyers then we're mostly caught by surprise bcause so early in the war they didn't really know that the Germans would launcha u boat campaign, secondly a lot of the time they were convinced that a ship struck a runaway mine. So the IRAI is good, wait until 1942 Then you'll see some destroyer action
