According to police, the teen had caught a wave and 54-year-old Ventura resident Mark Frame caught the same wave. Both surfers rode the wave.
When Frame came within 10 yards of the teen, he allegedly jumped on the teen's back and brought them both down crashing into the water. Frame is reportedly much larger than the teen.
When the two washed ashore, Frame was detained at the scene by several spectators and event coordinators until police arrived, according to the department.
One event coordinator told police that Frame had been warned by organizers to leave the contest area, where he was surfing, and Frame had ignored the requests to leave.
Police issued Frame a citation for battery. He was released at the scene.
The teen was not injured in the incident.