Watch a video report by ITV News Anglia's Kate Prout
Beneath the aqua blue waters of the North Norfolk coastline is a hidden world of marine magic.
Diver Chris Taylor has lived in Sheringham all his life and has snorkeled the offshore chalk reef since he was a teenager. Recently, he started filming his trips.
At 20 miles long and six miles wide, it is the largest chalk reef in Europe. It's a 100 million years old and teeming with life - edible and velvet crabs, lobsters, starfish, anemones and jellyfish can all be seen easily.
At low tide, you can swim out from the shore.