Sean Stevens, 17,  was in the Bilford Road area of Worcester when he was struck by Ryan Scott and fell backwards into the canal in March of this year.
Mr Scott was arrested for manslaughter but charges were later dropped.
Worcestershire coroner Geraint Williams recorded a verdict of accidental death.
He said the friends involved would be "scarred for life" by what happened.
More updates on this and other stories in Hereford and Worcester
A teenager was shadow boxing by a canal with friends when he was accidentally hit and fell into the water and died, an inquest has heard.