Surfers Healing is an organization which organizes day camps at the beach for autistic kids to go surfing. Nat loves boogie boarding, so I'd jump at the chance to get him on a surfboard to see what happens.
At first, I was skeptical about the "healing" part, but there are other kinds of healing than reversing the damage of autism. It would be a fun day at the beach, and that can only be good for Nat, and for the whole family. And seeing a disabled person doing things you didn't think they could: that's definitely a form of healing.