A Hub defense lawyer who specializes in OUI cases was “drunk and belligerent” when authorities boarded his pleasure boat Saturday night after a teen passenger jumped into Boston Harbor and had her right arm cut off by the propeller, prosecutors said today.

“They searched for her arm to no avail,” assistant Suffolk District Attorney Nicole Rimar said of the 19-year-old Auburn victim, one of a bevy of teenage girls aboard the Naut Guilty when it set sail for Spectacle Island, according to police reports released by Boston Municipal Court.

Rimar said a search warrant was executed on the boat, which was unregistered, “and large quantities of alcohol were recovered.”

Sunburned attorney Benjamin Parkhurst Urbelis, 33, of Charlestown, still wearing a green Celtics “Beat L.A.” T-shirt and his green, yellow and black-striped swim trunks, pleaded not guilty today to operating a boat while under the influence causing serious bodily injury, negligent operation of a boat, and operating a motorboat without a legally required identification number.

Rimar said Urbelis initially refused to submit to field sobriety tests, but four hours later consented to a Breathylyzer and blew a blood-alcohol level of .09.

Of his 13 passengers that day, five were 19-year-old girls, according to police. The list also included a 15-year-old boy and seven adults ages 21 to 33.

He was ordered to surrender his passport and was held on $75,000 cash – bail his attorney Dan O’Malley told the Herald would not be posted today. His client’s Andover parents left their son’s arraignment without commenting.

Rimar said the victim is in stable condition. She said the girl had jumped overboard to retrieve a seat cushion that had blown into the water sometime after 7:30 p.m., but the 30-foot Naut Guilty drifted “and unfortunately she was hit by the propeller.”

O’Malley said Urbelis has no criminal history. “He has strong ties to this community. There is nothing to suggest he would not return to face the charges.”

On the website of his lawfirm, Urbelis lists OUI cases as one of his areas of practice.

“If you are being investigated or are arrested for a motor vehicle offense, it is important that you NOT speak to law enforcement officials about your case,” he advises in a post about OUI defense on his website. “Very often, people think that the best approach is to be honest, forthcoming, and apologetic. In most aspects of life, that’s probably true. When dealing with potential criminal charges, that’s the absolute worst course of action.”

He also touts his own vigor as a defense lawyer.

“The most telling mark of Benjamin’s reputation is that many attorneys retain his services when they find themselves facing criminal charges,” his website notes.

Urbelis was out on the Naut Guilty with his 12 passengers on Saturday night when the young woman apparently jumped overboard near Spectacle Island.

Authorities said the woman’s arm was severed just below the shoulder by the boat propeller and she suffered injuries to her abdomen and face.

First responders applied a tourniquet to the critically injured woman and the marine fire crew rushed the victim to shore, according to Boston Fire Department spokesman Steve MacDonald. Rescue crews and authorities later searched around Spectacle Island for the young woman’s arm but couldn’t find it, MacDonald said yesterday.

Urbelis is due back in court June 26 for a pretrial hearing. If convicted, he faces up to 10 years in state prison.