The US Coast Guard has sent out several rescue teams, including an aircraft and two ships, to search for him but has had no luck yet.
The ship was intercepted by the US Coast Guard.
The US Coast Guard said it had sent investigators to confirm whether crude oil had begun to wash up on parts of the Louisiana shoreline.
The National Transportation Safety Board sent letters to the federal agency that regulates bus and truck safety and the US Coast Guard citing accidents in which sleep apnea was a factor.
The US Coast Guard reckons that 5,000 barrels of oil are leaking out every day, though this is really an informed guess.