SAN MATEO (CBS SF) — A 48-year-old San Mateo man has been charged with boating under the influence after his watercraft allegedly crashed into a teenage kayaker inflicting critical injuries, authorities said.

San Mateo police said a 15-year-old was kayaking with a friend on the San Mateo Lagoon Sunday when he was struck by a motorized boat.

The teen suffered serious injuries and was quickly transported to the nearest trauma center.

Meanwhile, the boat driver, 48-year-old Stephan Chiari of San Mateo, was found to be under the influence of alcohol and arrested at the scene. Though alcohol was determined to be a factor, the collision remains under investigation.

The teen remained in critical condition at the trauma center on Monday.