Mark-Paul Gosselaar: Shirtless at Oakley's Learn to Ride!

Mark-Paul Gosselaar goes surfing with his son Michael at the Oakley Learn to Ride Surf event on Friday (July 22) in Dana Point, Calif.

The 37-year-old Franklin and Bash actor was also joined by his daughter Ava at the beach.

After surfing all day, they later hung out in the Oakley tent where his kids went straight for the chocolate Muscle Milk to refuel.

Also pictured inside: Lindsay Lohan, who checked out the scene on the beach before enjoying Kate Voegele‘s acoustic performance at the Oakley private dinner that night.