An Irishman, accused of pushing another man overboard on a holiday party cruise in San Francisco Bay, pleaded guilty to involuntary manslaughter.
A US jury last year acquitted William Monaghan, 29, of first and second-degree murder following the death of Mr Lionel Voillat during the cruise in October 2002.
The jury, however, remained deadlocked on charges of voluntary manslaughter and the judge declared a mistrial.
Despite objections by prosecutors who had sought a voluntary manslaughter conviction punishable by as many as 11 years in prison, Judge Philip Moscone accepted Monaghan's plea, saying the outcome was the "best for all concerned".
Mr Voillat, a 30-year-old Swiss native, drowned after Monaghan threw him off a boat during the Hallowe'en costume-party cruise.
Witnesses said the two men quarrelled after Monaghan hugged Mr Voillat's girlfriend. Monaghan said he was reacting to an attack by Voillat.
He will be deported back to Ireland.