Environmental activist Erin Brockovich, portrayed in a 2000 film about her fight over the pollution of a California town, has been arrested on suspicion of boating while intoxicated.
Ms Brockovich, 52, was arrested at Lake Mead, near Las Vegas, on Friday night after breath tests showed her blood-alcohol level was just over twice the legal limit, said Edwin Lyngar, spokesman for the Nevada Department of Wildlife.
A game warden noticed she was struggling and needed assistance while trying to moor her motorboat at the Las Vegas Boat Harbour, he said. Ms Brockovich had been out on the boat with a male companion but was alone when she tried to dock it.
"She was not sure how to manoeuvre the boat into the dock," Mr Lyngar said. "It's a simple thing if you can think clearly. But if you add alcohol and unfamiliarity of the area, it can all cause serious problems."
Ms Brockovich, of Agoura Hills, California, was released from the Clark County Detention Centre after posting 1,000 dollars bail. Under Nevada law, a first-time offence of boating while intoxicated is a misdemeanour that draws fines from 1,000 to 2,000 dollars. Authorities were unsure whether it was Ms Brockovich's first arrest on the charge.
Ms Brockovich's efforts to sue Pacific Gas & Electric for polluting the water supply of a small Southern California town were adapted into a big-screen story, Erin Brockovich, with Julia Roberts in the Oscar-winning title-role.
Last year Ms Brockovich was back on the big screen in the documentary Last Call At The Oasis, which explores challenges related to the planet's dwindling and increasingly polluted water supply.
In a statement, Ms Brockovich stressed that she did not operate the boat in open waters and said "there was no public safety risk". She added that the arrest "was clearly a big mistake".
"At no time was the boat away from the dock and there was no public safety risk," she said. "That being said, I take drunk driving very seriously, this was clearly a big mistake, I know better and I am very sorry.
"After a day in the sun and with nothing to eat it appears that a couple of drinks had a greater impact than I had realised."