The writer and walker Linda Cracknell joins Helen Mark along North Devon's exposed and rugged coast to seek out the traces of her maritime roots. Her family sailed out of Braunton on the Torridge and Taw. This estuary, which drains large parts of Exmoor and Dartmoor, has the second largest tidal range in the world, and Linda is fascinated by the intertidal zone that's exposed at low tide, a place of wrecks and wader birds.

Particularly treacherous is the Bideford Bar, a shifting bank of sand and shingle that sits at the entrance to the estuary, and which has claimed many lives over the years. Helen rows out towards it with the Appledore gig racing team, who love to rise to the challenges the estuary poses. Helen and Linda also meet the Hartnell family who farm Braunton's Great Field, an unenclosed system of narrow strips that dates back past medieval times to the Saxons.

Forming the buffer between the sea and the Great Field are Braunton Burrows, a richly varied sand dune habitat, home to orchids and many other rare plants. Botanist Mary Breeds and her husband John, former warden for the Burrows, show Helen and Linda the plants, while Army landrovers rattle by on training exercises.

Producer: Mark Smalley.