If you've never heard of the Supergirl Jam, it is a competition of the world's top female athletes in surfing, skateboarding, snowboarding and in-line skating.
Here's a video promoting last year's Supergirl Jam:
The Supergirl Jam is the industry’s only large-scale, all-girls action sports competition and is designed to celebrate female strength, independence and empowerment.
Tomorrow, the Supergirl Am Jam (skateboarding), is the first of three events this summer at SKATELAB, a premiere Southern California skate park.
On August 14th, in Oceanside, CA the Supergirl Pro Junior surfing competition will take place followed by snowboarding on August 22nd.