large amounts of Dulse Mid Shore Line, some as long as 25cm
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Doesn't look like Dulse to me, looks more like one of the wracks.
The two photos posted here are different seaweeds. The one on the right is a red seaweed, Lomentaria articulata. It is generally better to do two different posts to avoid confusion.
Lat/Lng: 50.4, -3.6
OS grid ref: SX9363