Double-hull tankers are expected to be the standard by 2020. The Exxon Valdez was a major wake-up call.

Governments, by denying docking facilities, could eliminate much of the problem with 'rust bucket' ships, but forcing poorer countries to comply may be a problem. All major petroleum shipping concerns are demanding double hull tankers.
The tremendous increase in demand by China and India has put much pressure on tanker fleets. This may contributd to the use of old tankers, but I don't know Chinese or Indian regulations or if they are enforced.

At the time you cite, nearly 40 years ago, regulations were lax, but have changed for the better. Shipping firms try to avoid dangerous coastal waters and currents, but there is no way to guarantee accident-free shipping; keeping accidents to a minimum, through regulations, is the best that can be done.