An environmental group is warning Scotland's coastline remains at risk, on the 20th anniversary of the Braer tanker disaster.
The ship ran aground off the Shetland Isles on 5 January, 1993, spilling almost 85,000 tonnes of crude oil.
Many birds died but the weather limited the full extent of the damage as much of the oil was swept out to sea.
WWF Scotland said a major incident was never far away. The UK government stressed it paid to ensure tug cover.
The Braer grounding prompted an increase in emergency cover but recent cutbacks have left one emergency tug for the whole of Scotland.
WWF Scotland said deep-water drilling also posed more risks.
Spokesman Lang Banks said: "The Braer disaster was most definitely an extremely close shave in environmental terms.
"Had it not been for the weather, the spill would have caused much more widespread environmental and economic damage - but we cannot rely on the weather to get us off the hook next time.
"As it was, thousands of birds are still estimated to have perished and marine wildlife and marine mammals were also badly affected.
"Despite the passage of some 20 years, the sad fact is that much of Scotland's marine environment remains just as much at risk from oil and other pollution."
Scottish environment secretary Richard Lochhead said: "Twenty years ago, Braer was a wake-up that everything was not right when it came to safeguarding our waters.
"Thankfully, the Shetland environment has recovered and such major incidents are very rare. Safety - both for the marine environment and those who work offshore - must be a priority.
"Over the past two decades there have been significant improvements in the safety of the oil and gas industry. The highest standards must be maintained and that's why Marine Scotland works closely with other agencies and partners to ensure marine protection remains paramount.
"As we mark the 20th anniversary of the Braer disaster we must continue to learn lessons and ensure that our precious marine environment, and those using it, are properly protected."
The UK government has rejected any claims that Scotland's coastline was not adequately protected.
Lib Dem Orkney and Shetland MP Alistair Carmichael said: "The government understands perfectly well the dangers faced by island and coastal communities, that's why we pay for the tug that is currently stationed in Orkney as we speak.
"We're also working with the oil industry to get extra cover for them."
- 30 September 2011
- 5 January 2003
- 15 April 2001