BOSTON — An attorney who specializes in defending people charged with drunken driving pleaded not guilty Monday to operating a boat while drunk after a passenger went overboard and lost her arm in the propeller.

Benjamin Urbelis, 33, of Boston, was held on $75,000 bail and ordered to surrender his passport at his arraignment.

Authorities say Urbelis was operating his 29-foot boat Naut Guilty on Saturday night in Boston Harbor when the 19-year-old woman jumped in the water to retrieve a cushion that fell overboard.

The woman’s arm was caught in the propeller as she tried to get back on the boat, severing her arm above the elbow and also injuring her face and abdomen. She was taken to Massachusetts General Hospital, where she is recovering.

At his court appearance, Urbelis wore swim trunks and a Boston Celtics T-shirt that read “Beat LA.” He tried to avoid being photographed, but the judge ordered him to step forward, The Boston Globe reported.

A prosecutor said Urbelis was “drunk and belligerent” while police interviewed him after the accident and that a search warrant executed on the boat turned up large quantities of alcohol. About four hours after the initial distress call, Urbelis agreed to take a breath test and had a blood alcohol level of 0.09, Suffolk County District Attorney Daniel F. Conley said. The legal limit for operating a vehicle in Massachusetts is 0.08.

Urbelis’ lawyer argued his client is an accomplished professional and not a flight risk. Along with being an attorney, Urbelis is part owner of a Boston bar and founder of a nightlife consulting company, according to a website for his law practice. The website boasts that 80 percent of the cases his practice has brought to trial resulted in not guilty verdicts.

Prosecutors said Urbelis was operating the boat with 12 passengers aboard when the woman was injured. Others on the boat ranged in age from 15 to 33, including several young women. The boat was later towed to a police dock for investigation.

After the woman was taken to the hospital, firefighters searched but failed to find her arm. Fire Department spokesman Steve MacDonald told the Globe that medical responders “did a great job in trying to give the victim a chance.”

Urbelis is due back in court on June 26. He is charged with causing serious bodily injury while operating a boat under the influence of alcohol, negligent operation of a boat and operating a motorboat with no identification number.