Is it really worth the effort to raid harbours when the opportunity to do so arises?

[Paul Riley]

Having just completed the 24 hr patrol in AN26 I am now considering my next move.I WAS going to risk a trip to Scapa Flow and inspect what may be in there but I got a radio message from base instructing us not to attack any capitol ships,at least for the time being,ruling out a trip to S.F.
I have decided instead to make for Aberdeen and lurk about 5-6km from land to intercept any shipping that may be heading there.Now I dont normally opt for harbour raids,but something is compelling me to do so as my patrol so far has been quite uneventful save for a Granville sinking a few days ago.I am wondering,is it really worth the effort to raid harbours,and does anyone have any experience of patrolling just off Aberdeen?,whats the traffic like?

NOTE - I have compiled a notebook containing all previously known ship lane co ordinates from older campaigns and I may have a browse through it yet,I may be close to known shipping lanes