Scooter the rescue dog is competing in a The Surfdog surf-a-thon, run by the Helen Woodward Animal Centre in San Diego, California.
His owner Kirstie Martin took him in as a therapy dog to support her with the effects of PTSD following a career in policing.
She hopes Scooter's success will encourage others to speak up about their mental health.
Scooter has been learning to surf for just one year and this is his first competition.
When he's not surfing he also visits St Richards Hospital in Chichester cheering up patients and staff.
Kirstie says Scooter has helped her talk about her feelings.