Blyth beach, south of Blyth town is open and sandy. It can fish at all states of the tide but a couple of hours either side of low water are usually the best. The north end can be more sheltered than the south and better when the sea pick up a bit. Further south again you have Whitley beach which can be a bit rocky in places. Fish this at low water, the rougher the sea the further north you should fish it. By the time the sea is really rough, you can fish the north end at high water.
Next stop is Tynemouth beach. This is worth a look when the sea is too rough for Blyth beach but not quite rough enough for Whitley. Park on the ramp at the north end and fish the skeer in the middle of the beach or anywhere there looks to be a hole sheltered from the back breakers.
Beaches have their day when the sea is rough, but you miss a lot of opportunities ignoring the rocky marks in between.