Officials are now looking into accusations that 38-year-old Dylan Greiner also took photos of young girls at the Boys and Girls Club in Santa Cruz.
Police say they found more than 500,000 images and videos on Greiner's computers.
Detectives say they have received calls and emails from over 100 concerned parents throughout California and the U.S.
They're asking parents to send an email to firstname.lastname@example.org and include the following information -- parent name, address, home telephone, cellular telephone, child's name, child's age, dates of visit at the surf school, and appropriate image of the child.
Grenier appeared in court Wednesday but did not enter a plea.