Two teenage brothers and a cousin have been jailed for killing a fisherman in the River Thames.
Scott Wilkinson suffered "catastrophic head injuries" when he was attacked near Sunbury Lock in Surrey on 27 July 2016, Guildford Crown Court was told.
Shane Crawt, 19, and Lenny Crawt, 18, were convicted of murder and jailed for life, with a minimum 15-year tariff.
Their cousin Charlie Smith, 25, was jailed for 13 years for manslaughter.
During the trial, the court heard the trio boasted they had "killed someone tonight".
Mr Wilkinson had been camping in an area known as "Donkey Island" when he was attacked.
His medical heart monitor recorded an increased heart rate, which was "potentially consistent with an adrenaline drive caused by the attack" at about 23:20 GMT, and the following day the readings were "inconsistent with life," the Crown Prosecution Service said.
His body was found floating in the water near his tent.
Shane Crawt, of Purley, south London; and Lenny Crawt, of West Molesey, Surrey; had denied murder.
Smith, of no fixed address, was acquitted of murder, but convicted of manslaughter.