John Cota, the pilot of the Cosco Busan container ship when it collided with the Bay Bridge in 2007 and set off a major environmental disaster, has been trying for years to renew his mariner's license.

When Cota, a Petaluma resident, pleaded guilty to two misdemeanor environmental crimes in 2009 and served 10 months in prison for it, it seemed likely to mark the end of his career as a merchant mariner.

But Cota, 64, has been working with his attorneys for years to have his mariner's license renewed, and doesn't seem ready to give up yet, according to a recent article in the San Jose Mercury News.

The federal Coast Guard license is different from the state bar pilot's license that Cota had when he steered the Cosco Busan, but it is a prerequisite for having a pilot's license. The high-level Coast Guard credentials Cota is seeking to renew would allow him to fill numerous roles on commercial ships, such as captain and first mate.

The Coast Guard confirmed this week that Cota has been attempting to renew the mariner's license that he had essentially turned in for safekeeping after the spill, and that it had issued a final denial of the request in February of this year.

In issuing its denial, the Coast Guard said Cota did not meet the medical standards or professional qualifications required and also referenced his criminal conviction in the Cosco Busan spill, as well as his role in grounding another ship in 2006.

Dan Dewell, spokesman for the Coast Guard, explained that Cota's license had never actually been revoked or suspended.

Shortly after the spill, in December of 2007, the Coast Guard asked Cota to turn in, or "deposit," his license to ensure that he didn't use it, saying in a press release that "the service believes he is not physically competent to maintain it."

As time passed, Cota's license, which was still valid even though he wasn't able to use it, was set to expire. At that time, Dewell said, Cota began trying to renew it, and though his requests were denied, continued appealing the decision until a final denial was issued on Feb. 13.

Cota did not return an e-mail seeking comment, nor a call made to his wife, Councilmember Teresa Barrett. However, the Mercury News quoted his lawyer, John Meadows, as saying that Cota was not giving up on the license and would take "all available remedies," including, possibly, a lawsuit.

Cota has paid a toll for the spill, which resulted in abot 53,000 gallons of bunker fuel being emptied into the bay. A 2008 report by the state pilot commission pointed to pilot error as a cause of the spill, citing a series of mistakes. He was also named in numerous civil lawsuits, most of which appear to be settled now.

In April, the owners and operators of the Cosco Busan container ship filed a lawsuit against pharmacists from a former Petaluma Longs Drugs, who they say gave the drugs to Cota that apparently clouded his judgment.

Cota made his career on the water, working as a bar pilot since the early eighties and holding credentials from the Coast Guard as early as 1966. Bar pilots are state-licensed mariners who board large ships passing through the bay to help their captains steer through the unknown waters, earning about $450,000 a year for the high-risk work.