Just been down Roker pier me and my mate had arrived at 5 and left at half ten had 21 mackeral between us, could have had 22 but one of mine fell of. Lots of coleys boiling to the top for the sprat. There had been only 6 caught by my mate earlier on in the day and then one after he had left as soon as we got there we were banging them out for fun well so it seemed and then it just died off but the terns were going balistic just out of casting distance, a lad also next to us caught 5 mackeral as well. I was also fishing Shields pier yesterday, only had coalies on feathers but lads were catching launce at the small wall for fun until the tide stopped running and then it wenyt dead, there was only one mackeral i seen yesterday on shields. So i can't see how you won't get any mackeral at hartlepool as you normally get them before sunderland do so all you can do is try and hope for the best.
Hope this information helps mate