At the Rancho Seco Recreational Area south of Sacramento, excited middle and high school students are busy making last minute adjustments to their solar-powered boats using drills and duct tape.

The competition is open to all of northern California, though this year most of the teams are from the Central Valley. Some have rigged canoes with angle-adjustable solar panels, and another team built a catamaran-style boat from scratch using high tech foam and fiberglass.  There's a hefty rowboat that took people to carry to the water's edge, and an outrigger-type set-up painted like the American flag.

And one student group built their craft entirely from Styrofoam:

That's Rubina Sethi from Laguna Creek High School. Once in the water, the carved styrofoam block zips along driven by a propeller powered by solar energy. 

DelBono: "The primary goal is to get students interested in learning about renewable energy using solar as the vehicle, literalyl as the vehicle today. And you can just see how excited they are, it's amazing."   

The students competed in a slalom event, a speed race and an endurance run. DelBono says she hopes to make the solar-powered boat regatta an annual event.