The 16th annual Great Cardboard Boat Regatta launched the holiday week June 28 as Lake Ellyn Park filled with entrants and spectators. "It's the kickoff of the Fourth of July festivities," said Mary Defiglia of the Glen Ellyn Park District. "It's a total family environment." The concept is for participants to "do more with less" in building boats from cardboard, organizer Terry Mathiasm said. "It stresses creative problem solving in order that ideas might be turned into reality."