A jellyfish filmed swimming off the coast of Cornwall is thought to be the biggest ever caught on camera in Britain. The four-foot wide barrel jellyfish, which is also known as the dustbin-lid jellyfish, was filmed by diver and archeologist Robert Lenfert. Robert, 42, and his wife Natasha, 39, met the giant creature off Pendennis Point, near Falmouth, Cornwall. The pair swam beside the giant sea beast for half an hour as it glided through the water.