Douglas Kersten, 43, was sentenced to three to six years in prison on his February guilty plea to first-degree vehicular assault and felony driving while intoxicated in the May 18 crash.
State Supreme Court Justice John L. Michalski imposed the prison term on Kersten, who had faced a maximum of 3½ to seven years. The judge also fined him $5,000 and ordered his driver's license revoked.
Prosecutors said the crash occurred after Kersten, another man and a woman had spent the morning and early afternoon drinking at a party at Lake Erie Beach in the Town of Evans. They said Kersten stole the woman's car keys and drove off with the other man.
Kersten lost control of the car, which vaulted down an embankment along the lake in Hamburg, ejecting his companion who suffered a traumatic brain injury, prosecutors said.
Kersten punched a good Samaritan who tried to help him, prosecutors said. He then ran away and waded into the lake where the Erie County Sheriff's Office helicopter was called to assist Town of Hamburg police in rescuing him.
Police took him into custody and obtained a court order to draw his blood. Testing showed he had Xanax, a drug prescribed to treat panic and anxiety disorders, and marijuana in his system and that he had a blood alcohol content of 0.16 percent, which is twice the legal limit for DWI.
His five previous felony DWI convictions date from 1989 to 2009, according to Assistant District Attorney Beth A. Solek.