Heidi Klum -- Back in Rough Waters After Ocean Rescue

Heidi Klum ain't afraid of no stupid water ... 'cause just three days after saving her son and two nannies from a dangerous rip tide in Hawaii, Klum got back into rough waters ... at Disney's California Adventure.

It's a pretty brave move considering the frightening scene in Oahu earlier this week ... when Heidi sprinted into the ocean to pull her son Henry and their two nannies out of the surf, while wearing nothing more than a skimpy bikini.

In fact, the water was so rough that day, her boyfriend Martin Kristen could be seen struggling to catch his breath on the shore after the terrifying incident.

But there was no water rescue necessary in California on Wednesday ... when a fearless Heidi was seen laughing her way through Grizzly River Run with Martin and her kids.