Future America's Cup sailors seek national bragging rights in Youth Cup By Noel Randewich SAN FRANCISCO (Reuters) - Ten catamarans from eight countries battled in scrappy fleet races on San Francisco Bay on Sunday in the Red Bull Youth America's Cup, with American and New Zealand sailors dominating the first day of the regatta. That was one of the few parallels with the coming final competition for the 162-year old trophy between Oracle Team USA and Emirates Team New Zealand that starts September 7. The crews in the Youth America's Cup are the best up and coming yachtsmen in each country. That made it easy to root for a boat and offered an alternative high-thrill spectacle to the racing that led up to the main two-boat event, which has been plagued by mishaps and controversy. American Youth Sailing Force, one of two U.S. teams, established an early lead to win the first of two races on Sunday on San Francisco's gusty bay in the first ever youth-version of the America's Cup. Full Metal Jacket Racing, one of two teams from New Zealand, won an action-packed second race, with Swedish Youth Challenge taking second place after a close fight against the second New Zealand crew - NZL Sailing Team - and France's Next World Energy. Participants in the Youth America's Cup are rising stars in competitive sailing, many of them Olympic athletes. All are between 19 and 24 years old. Unlike in the America's Cup regatta that started in July and culminates in September, sailors in the youth regatta must hold passports for the countries where their teams are based. Teams in the Youth America's Cup are sailing high-tech, 45-foot catamarans called AC45s, smaller versions of the 72 footers called AC72s that are sailed in the America's Cup regatta. The AC45 are one designs built by one boatyard in New Zealand. They share the same design, weight and sail plan. The team graphics and crews set them apart. The AC72 is a box rule, leaving room for the teams to build what they hope will be the fastest boat, while conforming to strict length, beam and sail height rules. While races in the America's Cup are a match between two boats going head to head, the Youth Cup, which continues through Wednesday, is fleet racing, with all teams competing at once. Full Metal Jacket skipper Will Tiller said that having 10 boats competing at once made for crowded sailing and difficult maneuvering on Sunday. You've got to scrap for every position. The boys have to really fight hard on the boat to execute the maneuvers. There's a lot of physical work out there," he said. Organizers hope that establishing a youth version of the America's Cup will give young participants a direct line to eventually join America's Cup teams. When software billionaire Larry Ellison's Oracle team won the Cup in 2010, it gained the right to set certain rules. Ellison chose to defend the trophy in his home waters, the windy San Francisco Bay. Ellison's team came up with the idea for the 72-foot cats, which can hydrofoil across the waves at 50 miles per hour but are extremely fragile and hard to handle. That the twin-hulled boats were dangerous became tragically clear in May, when a sailor was killed in the capsize of an Artemis Racing AC72. In the wake of that accident, teams and organizers briefly considered switching to the smaller AC45s but discarded the idea in favor of other measures to make racing with the AC72s safer. The radical design of the AC72s helped push the cost of fielding a strong challenge in the America's Cup above the $100 million mark, and the number of teams dwindled from the 12 to 15 originally anticipated to just four. After the accident Sweden's Artemis needed time to prepare a second AC72 and missed all but four of its scheduled races in the Louis Vuitton Cup challenger selection series. That led to several one-boat races that were a disappointment to spectators as Italy's Luna Rossa Challenge and Emirates Team New Zealand sailed the course alone to win points necessary to advance. New Zealand, which easily dominated Luna Rossa and Artemis to win the Louis Vuitton Cup on August 25, will now attempt to wrest the coveted trophy from Oracle in a series of 17 races starting on Saturday. If New Zealand wins the Cup, team managing director Grant Dalton has said he will use the defender's right to set rules to force teams in the next America's Cup to use sailors from their home countries. Such a nationality rule existed from 1980 to 2003 and for decades before that there was a tradition of boats, crews and designers being from the same country. Reporting by Noel Randewich; Editing by Alden Bentley