“The tide comes in at five vertical centimetres [about two inches] a minute,” he warns. “The difference between getting traction on the gravel or being swept away can be as little as 20 or 30 seconds There is no mercy out here. Anyone finding themselves trapped by the tide has to climb to the top of the tower as quickly as possible and await rescue. After 30 minutes or so, we reach a 40ft high metal platform on spindly seaweed-draped legs, which Andrew describes as the “point of no return”.
A few more steps and we find ourselves crunching through a limpet graveyard. The shells of mature limpets have been sorted and dumped by the currents that circle the island. “The water moves anti-clockwise, sculpting and sifting material along the way,” Andrew explains. “There are lots of distinct messages in the seascape that tell us which way the water has been blown.
It’s never the same, not even on two consecutive tides.”The speed and strength of the tidal flow make Jersey’s shore a dangerous place for the uninitiated. When the the tide comes in it does so in a pincer movement, racing unseen along sunken gullies to cut off the unsuspecting. Slowly, as our eyes adjust, we can make out shallow pools and dark shadows of rocks covered in glistening seaweed.After 15 minutes or so, the firm sand underfoot changes to gravel, a sign that we have moved beyond the shelter of the island into a higher-energy environment. Apart from the circles of light cast by our head torches, the only real illumination comes from orange pinpricks of streetlights further up the coast and the sweeping beam of a distant lighthouse. So what better way to explore it than by the light of a full moon?
As we step off the stone slipway, the moon is struggling to shine through patches of cloud. With the fourth highest tidal range in the world, Jersey doubles in size to 116 square miles every 12 hours when the English Channel drains away.
The landscape revealed by this fierce tidal flow looks distinctly lunar, according to Andrew, who is a marine biologist. Nothing crazy about that you might think – except that it is pitch black and one o’clock in the morning. We are here at this time because it is low tide, which means we can explore the undulating landscape of the channel island’s rocky seabed. Ryanair (0871-246 0000; ) flies from Stansted to both airports from around £130 return. Aer Lingus (0845- 084 4444, ) flies from London Heathrow to Cork from around £95.Where to stayCaragh Lodge at Killorglin (00 353 66 976 9115; ) is a beautiful country-house hotel on the shores of Caragh Lake, not far from Killarney and Tralee.
