I grew up in the village of St Bees about 10 miles south of Workington. We used to go fishing from the rocks at the base of the head at either high or low tide. It is meant to be good for cod but to be honest we never really caught much more than a few eels in winter (we were just kids at the time casting no more than 50 yards). In summer fishing was easier and we caught mackerel, pollack, garfish, bass and sea trout all from spinning.
I remember watching a couple of anglers pull out a number of cod but they were casting a good 150 yards. If you do go to St bees then take a lot of geer as you will loose lots on the rocky ground.
We fished Whitehaven pier a few times. One or two double figure cod are taken from here every year. It is a lot easier and more comfortable fishing than St Bees and you will loose less gear.
I'm sure there will be marks nearer Workington and further noth (Maryport?) but we never got the chance to fish them.