A container ship captain has been detained, suspected of steering the vessel while intoxicated, with a blood alcohol content level six times above the limit for mariners.

The captain of the MSC Jubilee IX — a 333-meter container ship flying the Liberian flag — was apprehended on Wednesday in Seattle, according to a Coast Guard news release issued on Saturday. The captain’s name has not been released.

A Puget Sound pilot aboard the vessel had reported to Coast Guard watchstanders that the captain was “displaying signs of intoxication.” The pilot and first mate navigated the vessel from near Everett, Washington, to the Port of Seattle “without incident,” as stated in the release.

After the ship moored at Terminal 5, a Coast Guard team and Coast Guard Investigative Service agents boarded the vessel.

The captain underwent a field sobriety and breathalyzer test, “which revealed that he was impaired more than six times the legal limit for commercial mariners,” according to the Coast Guard.

Federal law considers a person operating a vessel other than a recreational vessel with a blood alcohol concentration of .04% or higher to be under the influence.

The captain was detained and taken to the King County Jail. Charges have been referred to the King County Prosecutor for boating under the influence, and the investigation is ongoing. The prosecutor’s office did not immediately respond to a request for comment.

The vessel was given a relief captain and has since been cleared to resume operations, the Coast Guard said.

“The Coast Guard is proud to ensure the safety and security of the maritime transportation system,” Paul Shultz, Special Agent in Charge of the CGIS Northwest Field Office, said in a statement. “The Pilot’s immediate intervention mitigated significant risks and ensured the safe passage of the vessel.”