There were a great many of these clinging to the surfaces of the rocks in the rock pools on the beach.
No interactions present.
The picture is far to fuzzy to identify anything with confidence. As Murdo indicates, there may be more than one barnacle species present (some barnacles are white and others grey) but the colour difference might also relate to different year classes within species.
There is a beadlet anemone in the rock cavity (centre right) and a fuzzy limpet in the centre foreground of the image. The limpet is covered by barnacles
Thank you for your identification and comments. I took the picture originally for the beadlet anemone without realising that the barnicales could be identified or that there was a limpet in the foreground.
Lat/Lng: 52.93234, 1.30218
OS grid ref: TG220423
Found on the beach on the eastern side of the pier on a hot sunny day.