Shortly after 11 a.m., Chris Paicos was waiting to catch a wave under the Golden Gate.
"Sitting there and heard a couple of screams and I looked up and I seen the kid rolling the windows up on his way down, rolling the windows up and I closed my eyes, I didn't want to see him hit the water," Paicos said.
The term "rolling the windows up" is used to describe someone trying to maintain their balance.
The student splashed into the bay just a few feet from a group of surfers who helped get him to shore.
"As he paddled by, I asked him what he was up to and he said it was a stunt," Paicos said.
That infuriated some of the surfers.
"He could have killed someone, yeah, he landed about 20 feet away from a friend of mine and my friend was pretty mad," surfer Todd Smith said.
Still, with their help, the student managed to swim to shore and then climb the rocks on his own.
"He was swimming on his own, had a little assistance just to come back in, but he made it in alright, but yeah, it was pretty amazing," surfer Eric Wagner said.
An ambulance and several emergency units were waiting for him. He was taken to San Francisco General Hospital, but his injuries were limited to just some bruising. He will remain at the hospital for tests and a psychiatric evaluation.
The student had been on a field trip with 45 other students from Windsor High School. Two teachers were supervising the outing.
"It would be bizarre to do it in any circumstance; anybody who jumps from a bridge is obviously not in a right state of mind," California Highway Patrol spokesperson Chris Rardin said.
The Windsor Unified School District issued a statement Thursday afternoon saying, "Everything possible is being done to investigate and support all involved families and students. We are considering this an isolated incident."
The school district says parents were immediately notified of the incident and counselors are on hand for students.
"This is my second time witnessing a jumper, that one made it too," Paicos said.
Although several of the surfers say the teen said he jumped as a stunt, that has not been confirmed by CHP officers investigating the incident.