Sea potato

After a quick trip to the allotment we drove down to Mersehead for a walk and picnic on the beach. It was a lovely day , warm with sunny intervals. We arrived at low tide and as we strolled along the sand we could see lots of jellyfish left stranded. We also this curious sea potato, which I learnt was the empty shell of a sea urchin!
I went swimming , managing 20 lengths .