TEMECULA -- Gently cutting through the glassy lake, three solar-powered boats hummed through the water, barely leaving a wake as they raced toward the finish line.

The "sprint heat" was one of three contests 22 solar-powered boats entered during the Metropolitan Water District Solar Cup competition at Lake Skinner on Saturday. Ending today, the competition started Friday with opening ceremonies, followed by qualifying events. Saturday, the boats raced 200 meters for best time, and today, the boats will compete in a 90-minute endurance race around a two-kilometer course. Each team was also judged on reports they submitted to the MWD that explained how they made their crafts.

Julie Miller, MWD spokesperson and chairperson for the second annual event, said racing solar boats on Lake Skinner made sense since the lake is a main source for potable water.

"It also offers examples of creative ways we can protect our natural resources," she said. "Besides, this is a fun event -- the word has gotten out, and this year, we've doubled in size with a waiting list already started for next year."

Under large tents, teams set up shop and tinkered on their 16-foot-long boats, which bore the name of the water agency that sponsored it. Large solar panels basked in the sun -- recharging the batteries -- as young yachtsmen recharged their energy with food and sodas.

Each team was given $3,000, pieces of a hull and a two-inch thick manual to help build their craft. Some teams were still making last-minute modifications.

Nick Larsen bent over the hull of his boat, setting up the main drive shaft for electrical steering. Larsen worked as crew chief with his son, Joshua, 16, and the other five members of the Chaparral High School team. Their boat was one of five that didn't qualify Friday.

"We didn't have everything ready to go," he said, tightening a screw. "It was tough to get these kids together after school with all their other activities. But, the officials told us we could still race -- just not place."

Chuck Murphy, faculty advisor for Paloma Valley High School, said their boat was doing well.

"Everything's working good so far," said Murphy, whose team took 350 hours to complete the boat it started building in January. "These kids have a great attitude and great talent. They really made it happen."

Team member Cristina Bonnici, 17, said it was an interesting experience for her.

"I learned a lot about the electrical system," she said, nodding toward the boat nestled in its trailer. "It was a lot of hard work, too."

Flanking the boat, "Short Circuit," was a photo display of each step the team from Murrieta Valley High School took in making its craft. Engineering teacher Pete Matus said it took close to 100 hours after school to complete their task. Team member Chad Hardin, 17, said they didn't know what to expect.

"It sounded fun, but we didn't realize how involved it would be," he said, nodding toward the boat. "Once we had a direction to go in, it was nonstop."

Readying themselves for the next heat, the teams slowly maneuvered boat-laden trailers down the ramp, easing their craft into the lake. Grabbing a paddle, the "skipper" slid into the single seat and paddled toward the starting line -- which was actually a rope suspended from two wooden poles.

From the deck, parents and teachers barked out orders to the young mariners jockeying their boats into position and grabbing the rope marker to pull themselves into place. Unlike the familiar roar of a speedboat, the solar-driven crafts jutted forward and gently hummed across 200 meters, their top speed coming in at 13 knots or 15 miles per hour. Team mates cheered as they watched their skippers maneuver in the roped-off lanes.

"You know, we learned more than just how to build a boat," said Chad. "We learned how to work together. We learned how to be a team."

Solar Cup Competition

Where: Lake Skinner

Where: 33740 Borel Road, Temecula

Cost: Free

Sunday Activities:

9:30 to11:30 a.m. -- Endurance Races

11:30 a.m. to 1 p.m. -- Lunch

1 to 3 p.m. -- Endurance Races

3:30 p.m. -- Awards Ceremony