Seaweed covered in pustules means only one thing: it's the seaweed breeding season. This bit of Fucus vesiculosus (bladder wrack) landed next to an interesting artefact on the beach: an erratic. An erratic is a lump of rock that isn't part of the native geology. This piece of Shap granite was dragged here from the west coast by the glaciers in the last ice age.
And yes, I think the rock to the right contains fossil coral.