A container ship captain has been arrested, accused of operating the vessel while drunk with a blood alcohol content level six times the limit for mariners.

The captain of the MSC Jubilee IX — a 333-meter container ship operating under the Liberian flag — was arrested Wednesday in Seattle, the Coast Guard said in a news release Saturday. The captain’s name was not disclosed.

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

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

The captain completed a field sobriety and breathalyzer test, “which found that he was impaired more than six times the legal limit for commercial mariners,” the guard said.

Under federal law, a person operating a vessel other than a recreational vessel with a blood alcohol concentration of .04% or more is considered to be under the influence.

The captain was arrested and transported to the King County Jail. Charges were referred to the King County Prosecutor for boating under the influence, and the case remains under investigation. The prosecutor’s office did not immediately return 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.”