SeaSun Harbor, for now, is a kind of diorama on steroids.The table-sized city in miniature is the three-dimensional vision of middle schoolers from Merced, who were competing Saturday in an engineering contest at UC Davis.Tasked to come up with an energy-efficient future city, Amanda and Andrew Skidmore and Hannah Thibault devised one that floats in the ocean. That gave the McSwain Union Elementary School entry plenty of sun for solar power generation, and plenty of water. They planned reverse osmosis for desalinization.Their city was buoyed by a gas-filled balloon, the hydrogen separated from the water molecules that surround the city. Fuel cells provide some power.The contest was the Northern California regional contest for the National Engineers Week Future City Competition.More than 40 schools entered, but only 17 made it to Saturday’s model judging stage.Near the McSwain model, Aqua-Sol-Viente, devised by students from Hart-Ransom School of Modesto, proved to be stiff competition to overcome.With two of its creators on last year’s winning team, Hart-Ransom captured Saturday’s competition ahead of McSwain and St. Anne School of Porterville.The Hart-Ransom students will fly to Crystal City, Va., for the finals in February.Their seaside city offered solar, wind and water-current generation of electricity.Another city, dubbed Zero Pollution, used methane from farms surrounding a city and a giant water tank heated by focused solar rays.Though some of the ideas may seem fanciful, “you don’t want to stifle their imagination,” said Mike Thibault, a professional engineer who was mentor to the Merced team, and is parent to Hannah.Unlike an adult limited by thoughts of what won’t work, Thibault said, “They have this constant enthusiasm that says, ‘Why not?’ “He introduced the students to an engineer working on fuel cells for Pacific Gas and Electric.Other students went on field trips to water treatment and energy facilities.”They have a better understanding that there’s engineers behind so many things,” Thibault said.The students, however, can’t just dream. They have to be able to explain their cities in depth – transportation, food production, design, recreation. They make seven-minute presentations, then answer questions from specialists in various fields who serve as judges.There’s no faking it.”They were really good about giving me the details,” said one of the judges, Varsha Viswanath, a biomedical engineering student at Davis.Viswanath knew the value of specifics from her engineering classes, but also knew what the students were facing – she had competed in the same contest when she was in middle school in the Bay Area, before she decided to study engineering.The competition – which picks a different engineering problem each year – demands that students not only dream, but also learn the science, create computer-assisted models, write essays and master their presentations – sometimes a challenge for the shy ones.”But by the time they get to nationals, they’re like Vanna White,” said Lynda McGhie, the Northern California coordinator for the contest. © Copyright The Sacramento Bee. All rights reserved. Call The Bee’s Carlos Alcalá, (916) 321-1987.• Read more articles by Carlos Alcalá