'Amoco Cadiz, Eleni V, Christos Bitas - so far in Britain we've been lucky. But a really major oil disaster is inevitable - another Torrey Canyon. You can see it coming.' So say experienced seamen, and they should know. It's only a matter of time before somewhere along our coast, another supertanker Mts the rocks - or another tanker. The cause may be bad equipment, or bad training, or bad navigation, or plain bad seamanship. But the result will be certain: a thick black tide bigger than anything we've seen so far. And then who cleans up the mess? In tonight's programme, on film around our coast and from the studio in London, Jack Pizzey asks why have tankers been allowed to grow so huge, so clumsy, and so threatening, and asks if we will be well enough equipped to protect our beaches when ' the inevitable' happens?