A LITTLE oil on untroubled waters may provide pretty pictures in the form of concentric multi coloured patterns embellished with all the rich flamboyance of the rainbow. But black, crude, undiluted oil, afloat upon the surface of an, azure sea, is not a pretty sight at all, and the impact when it is washed ashore upon a golden beach is even worse.
In these circumstances, the oil is "muddy, ill seeming, thick, bereft of beauty," the epitome of the very concept of pollution.
Oil slicks have been a problem to a relatively minor extent ever since ships first began to use internal combustion engines for their motive power. But occasional nuisance assumed the potential for environmental catastrophe when large super tankers were built in the 1960s to transport great quantities of oil from distant oil fields to refineries in Europe and America.
This potential was realised for the first time 30 years ago today, when the 60,000 tonne tanker Torrey Canyon ran aground on the Seven Stones Reef between Land's End and the Scilly Isles on March 18th, 1967.
Weather conditions are very often the immediate cause of disasters like the Torrey Canyon. Equally importantly, they dictate the ultimate destination of the polluting effluent, and the efficacy of subsequent efforts to contain the slick and to clean affected areas.
In the open sea the movement of an oil slick is government mainly by the wind; it travels in the direction of the airflow at a speed of about three or four per cent of that of the wind itself. Closer to the shore, and in enclosed waters, tidal currents and other, local influences predominate in deciding which areas will be most affected.
In the case of the Torrey Canyon, more than 100 miles (of Cornish coastline were polluted by the 100,000 tonnes of oil that spilled into the sea when the vessel broke its back.
The damage was contained only when the ship was bombed from the air, to set fire to its remaining cargo. But Bit turned out to be merely the first of a long list of tankers which have caused environmental crises of this kind over the years.
Their names have a familiar ring. The Universe Leader caused havoc in Bantry Bay in 1974; the Christos Bitas discharged its load off Milford Haven in 1978, and the Amoco Cadiz was responsible for the greatest oil spill so far, losing over 200,000 tons of crude oil when it was grounded off the coast of Brittany in 1979.
The Kowloon Bridge came to grief off West Cork in 1986, and more recently we have had the Braer off the Shetlands and the Sea Empress, again off Milford Haven, just a little over a year ago.