Hi, tricky one this one, I sunk mine south of Portsmouth, check to see if there's a plus sign next to the port, expand to see which ships are stationed, often you will see the Ark stationed there. I waited for more than 2 weeks, 15 km south of Portsmouth, and low and behold 2 carriers appeared one after the other in opposite directions (neither of which was the ark
). Note that the hydrophone will pick up a task-force from quite a distance, around 12-18 km. You have the option to sneak in to the port and sink one while it's docked, however you will often find that the game won't count this toward meeting your campaign objectives.
The thing to remember is that you don't have to complete all the missions to successfully complete this campaign, the campaign will automatically end on the 1st June 1940 regardless. Good hunting
