Sorry to have to tell you Adrian,but the outer harbour is a complete no-go area,in fact they have closed the approach road and now have iron gates and a security man to check all entrants.
I have been in a couple of times in my Taxi to drop people off but was given a severe warning when seen trying to take some shots of a dive support vessel.You can get some shots of vessels
leaving the outer and inner harbours if you go to the pier plain car park on the Gorleston side of the river and take a short walk to the harbour mouth.Hope this is some help to you
Best regards TX2