Tidal Gates


The water has nearly drained out of the lock: fresh water, with a flat green smell. The wet stone walls rise. The modest turbulence ceases. A crack of light appears between the seaward gates and widens into a panorama of blue sea and green islands. Shove the control forward, feel the faint kick of the propeller as the lines come clattering down on deck. The boat slides out of the lock's darkness into the bright dazzle of the bay.

Point the nose at the breeze. Up goes the main, a cream triangle against the blue of the sky, backing at first, then filling into a lovely aerofoil as the topping lift comes off and the kicker goes on and the mainsheet comes in. The genoa rolls off the forestay with a bang. The cockpit sole tilts underfoot and we are off, surging away from the huddle of buildings on the shore, aiming at the gap of sea between a headland and an island a couple of miles ahead.

This is not an ordinary gap. It is the Dorus Mor, a tidal gate through which the enormous river of the north-going tide must squeeze. It is important to hit it at the right moment, which is why we have been hanging round in the basin inland of the sea lock in the smell of boat exhaust and other people's coffee.

But now the breeze is fresh and salt, and the boat is trucking at a steady six and a half knots. Six and a half knots, according to calculations involving square roots and faith, is something like maximum hull speed. But as the gap comes closer it is noticeable that the speed over the ground has climbed to seven knots. There is tide under us. Ahead, where the island comes closest to the mainland, white feathers of foam lie across the sea. Something highly advantageous is happening out there.

Another half mile. The heel steepens, and the genoa trimmer is lining up her telltales, and the GPS says nine knots, so two and a half knots of tide, and rocks on the shore are sliding past distant landmarks at unbelievable speed. To port and starboard the sea is tormented, occasionally forming standing waves that collapse and reform. The sea our bow cleaves is calm. To a gull overhead, though, it would look as if we were in the tail of a pool on a mighty salmon river, where the main current speeds into a vee of smooth water flanked by roiling eddies. We are channeling experience gained in featherweight canoes on the great rivers of Canada into taking seven tons of boat by the most efficient possible route through the first of the gateways guarding the beautiful northwest coast of Britain.

Ten knots on the GPS. A crash of overfalls, and we are through. A porpoise is here with us. Everyone including him is laughing, somewhere between relief and exhilaration.

But it is too early to laugh. Ahead, across half a dozen miles of turbulent sea, lies the strait known as the Corryvreckan, the next gateway, compared to which the Dorus Mor is child's play. The ancients claimed that the only way to survive it was to rig your vessel with the hair of virgins. That is as may be, but we are a well-found boat with a rig made of steel and polyester, which is stronger than maidens' hair any day. Furthermore the weather is clement; so we will take our chances.

And on we race to the Corryvreckan, on either side of which the mountains soar like pillars holding up the sky.

Sam Llewellyn, editor The Marine Quarterly.