We visited Norfolk in August 2013 and spent a day in Great Yarmouth.
We visited the beach. It was huge but very deceptive. The first 80% or so (the part you could see from the promenade) was lovely and golden and sandy. The remaining strip next to the sea (which you couldn’t see from the prom) was all pebble. It was very difficult and painful for the children to paddle in the sea barefoot. Clean but painful.