A REPORT released on the fifth anniversary of the Exxon Valdez oil spill recommends that tankers remain 56 kilometres to 104 km off the California coast, between Bodega Bay in the north and San Simeon in the south.
The recommendations are specially intended to protect the Cordell Bank, the Gulf of the Farallones and Monterey Bay national marine sanctuaries, Singapore's Business Times said.
The report was written by Richard Townsend of United States-based Townsend International, whose expertise is in vessel traffic safety, and Marci Glazer of the Centre for Marine Conservation's Pacific regional office.
''Thousands of vessels carrying billions of gallons of crude oil, petroleum products and hazardous substances pass through the sanctuaries en route to, or from, San Francisco Bay, southern California and other areas,'' the report said.
''At least 1,000 tankers enter San Francisco Bay each year. Every year vessels experience breakdowns in essential pieces of navigation and mechanical equipment during voyages. If the vessels are close to shore, or in busy traffic areas, equipment failures could have extreme consequences,'' it said.
These failures are made more troubling by the ageing vessels' poorly trained crews, inadequate inspection and oversights that are endemic to the world tanker industry.
''Under present practice, tankers and other ships may follow any route through coastal waters at the discretion of their masters,'' the report said.