Nick Crane confronts the terrifying power of the tides head-on as he paddles
for dear life in a kayak to conquer the fearsome, tidal rapids that swirl off
the island of Anglesey. Then in Liverpool, he discovers a remarkable but
forgotten machine used to predict the tides for the D-Day landings. Developed
over 100 years ago, this massive mechanical computer is capable of calculating
sea levels anywhere in the world many years in advance and with incredible
precision. As it is painstakingly pieced back together, Nick meets one of the
women chosen to operate it so many years ago.

Miranda Krestovnikoff ventures to Jersey for an expedition to the Seymour
Tower, a spectacular fortress that is transformed daily into an island outpost
at high tide. Miranda stays overnight in the Tower to await an exceptionally
low 'Spring Tide', when exotic sea creatures might be revealed. In Scarborough,
Tessa Dunlop challenges both changing times and the tide of fashion. She's
putting bathing suits to the test on the beach, from a Victorian lady's cotton
cover-up to a Swinging Sixties little nylon one-piece, as she explores the ebb
and flow of stylish swimwear over a century of textile innovation.

Mark Horton heads to Poppit Sands in Wales, where at very low tide the faint
outline of a huge stone structure mysteriously appears beneath the waves. Mark
explores the remains of this massive medieval fish trap, which was built more
than 900 years ago but lost as sea levels rose and only recently re-discovered.
Yet who was so famished for fish that they constructed this elaborate, sub-sea,
stone structure to harvest the bounty of the tides?