The National Transportation Safety Board determined yesterday that a medically unfit pilot, an ineffective master, and poor communications between the two were the cause of an accident in which the Cosco Busan container ship spilled thousands of gallons of fuel oil into the San Francisco Bay after striking a bridge support tower.

On November 7, 2007, at about 8:00 a.m. PST, in heavy fog with visibility of less than a quarter mile, the Hong Kong-registered, 901-foot-long container ship M/V Cosco Busan left its berth in the Port of Oakland destined for South Korea. The San Francisco Bay pilot, who was attempting to navigate the ship between the Delta and Echo support towers of the San Francisco-Oakland Bay Bridge, issued directions that resulted in the ship heading directly toward the Delta support tower. While avoiding a direct hit, the side of the ship struck the fendering system at the base of the Delta tower, which created a 212-foot-long gash in the ship's forward port side and breached two fuel tanks and a ballast tank.

As a result of striking the bridge, more than 53,000 gallons of fuel oil were released into the bay, contaminating about 26 miles of shoreline and killing more than 2,500 birds of about 50 species, according to NTSB. Total monetary damages were estimated to be $2 million for the ship, $1.5 million for the bridge, and more than $70 million for environmental cleanup, according to the board.

"How a man who was taking a half-dozen impairing prescription medications got to stand on the bridge of a 68,000-ton ship and give directions to guide the vessel through a foggy bay and under a busy highway bridge, is very troubling, and raises a great many questions about the adequacy of the medical oversight system for mariners," said Acting Chairman Mark V. Rosenker.

In its determination of probable cause, the Safety Board cited three factors: 1) the pilot's degraded cognitive performance due to his use of impairing prescription medications; 2) the lack of a comprehensive pre-departure master/pilot exchange and a lack of effective communication between the pilot and the master during the short voyage; and 3) the master's ineffective oversight of the pilot's performance and the vessel's progress.

Contributing to the cause of the accident, the board cited 1) the ship's operator, Fleet Management, Ltd., for failing to properly train and prepare crew members prior to the accident voyage, and for failing to adequately ensure that the crew understood and complied with the company's safety management system; and 2) the U.S. Coast Guard for failing to provide adequate medical oversight of the pilot.

"Given the pilot's medical condition, the Coast Guard should have revoked his license, but they didn't; the pilot should have made the effort to provide a meaningful pre-departure briefing to the master, but he didn't; and the master should have taken a more active role in ensuring the safety of his ship, but he didn't," said Rosenker. "There was a lack of competence in so many areas that this accident seemed almost inevitable."