Aristotle Onassis of his fleet, while having trouble managing their own fleets, which operated under US flags and thus at high cost. The high profitability of the Onassis fleet has been attributed in large part to his disregard for standards that normally govern international shipping. For example, after his Liberian registered tanker SS Arrow ran aground and spilled oil into Chedabucto Bay in 1970, still the most significant oil spill off Canada’s East Coast (about 25% of the amount spilled by the Exxon Valdez in Alaska in 1989), there was a Commission of Inquiry. Led by Dr Patrick McTaggart-Cowan, executive director of
Exxon Valdez oil spill effectively a bill of attainder, a regulation that was unfairly directed at Exxon alone. In 2002, the 9th Circuit Court of Appeals ruled against Exxon. As of 2002, OPA had prevented 18 ships from entering Prince William Sound. OPA also set a schedule for the gradual phase in of a double hull design, providing an additional layer between the oil tanks and the ocean. While a double hull would likely not have prevented the "Valdez" disaster, a Coast Guard study estimated that it would have cut the amount of oil spilled by 60 percent. The "Exxon Valdez" supertanker was towed