Another algae but....?

A pleasant wander over to the loch to look for something interesting, the wind was cold but then the sun appeared and it felt 'warm' when out of the wind. I came across this algae and feel it must be a seaweed, but can't identify it with any certainty. To see it lying here with the other seaweeds in two different stages was fascinating and have considered a dried form of a lettuce seaweed?

Thank you to gens who has ID it as a lichen - Lobaria pulmonaria.