HOULTON – The seventh annual Northern Maine Soap Box Derby will draw hundreds of racers competing in two different divisions all day today. The action begins at 7 a.m. and continues until 4 p.m. at the hill near the John Millar Civic Center with the awards ceremony at the center at 5:30 p.m. The two classes of racing are stock (novices, ages 9-16) and super stock (advanced, up to age 16).