Now the great oil spill so long feared has come to pass - but it has nothing to do with the islands' involvement in the oil boom.
The stench of crude can now be smelt in the Shetland capital, Lerwick, 20 miles to the north of the wreck of the Braer. The oil is spreading up both coasts of the long, narrow, southern half of Mainland. It lies on seaside pastures and cabbage patches, creates iridescent patterns on inland puddles, coagulates on windscreens. Sullom Voe, Europe's biggest oil terminal and one of the islands' biggest employers, is at the other end of the main island. One or more tankers a day come and go from this deep water harbour, exporting 800,000 tonnes of oil a week brought in by two undersea pipelines from North Sea fields. The islands' council was heavily involved in the venture, acquiring the land and sponsoring a Bill to allow the gigantic development.
But the Braer had no connection with this. It was simply taking the shortest route from Norway to Canada through a 22-mile strait south of Shetland.
It almost missed as it drifted, powerless, in a gale. A minuscule difference in winds, tides and waves would have taken it just clear of the rocks and along the coast, giving the tugs several more hours to halt it.
The islands were aware of the danger from the sea. For over a year the Shetland Islands Council has been planning an international conference on managing the marine environment. Ageing tankers and the competence of crews is one of the main themes.
Because of its involvement in the industry, Shetland has one of Britain's largest concentrations of oilspill fighting muscle and expertise. Yet the 22,500 islanders now face the worst of worst-case scenarios - a fully laden tanker hitting cliffs in a near hurricane and no prospect of calm weather. There is little they can do.
Largely thanks to oil, the 15 inhabited islands in the group have unemployment levels under the average for Scotland and its other islands, reversing the long trend of depopulation.
As well as Sullom Voe, there is the harbour at Lerwick used by North Sea support vessels and three airports kept busy with helicopters and aircraft taking workers to and from oil platforms. Fishing, fish farming and fish processing employ more people. Farming is Shetland's third largest industry. Both are under grave threat from the spill. It comes as the decline in North Sea oil gathers pace. The amount of crude leaving Sullom Voe is now 40 per cent down on what it was at its peak. Employment will gradually fall off. The council's economic development officer, Jack Burgess, said: 'The question of what replaces it is a very difficult one.' Gigantic quarries are mooted but they are environmentally controversial. If Shetland has to rely more on tourism, then the Braer's monstrous visitation is even more of a disaster.
The Sullom Voe terminal itself has had an excellent environmental record. The only severe spill came within three months of it opening in 1978, and that was tiny compared to what has happened this week.
The islanders are frightened, disgusted, confused and busy coping with the spill and the invading press and oil pollution experts. The convenor of Shetland Islands Council, Edward Thomason, tried to reassure them yesterday. 'Our economy and our society could be at risk. But there is a future in Shetland for any young person that wants to stay. We've demonstrated our ability to solve problems in the past . . . it's a pretty good place to be.'