David Heintz is known for his elaborate boats in past years -- riverboat casinos and pirate ships. This year he will set out on the lake with 10 people aboard their latest vessel, which is kept afloat by 900 milk cartons underneath its wood frame.
Altogether, Heintz and his friends have spent three months building their boat in a friend's extra-long driveway. They used 2,500 milk cartons -- some from the Aquatennial, some donated, and a good number from their own families.
The milk carton boat races started in 1971. According to the rules, participants can use wood and other materials to build the frame of their boats, but floatation must be provided by plastic or cardboard milk cartons.
The boat must be people-powered, and everyone has to wear a personal flotation device approved by the Coast Guard.
Awards are given in several races, including children's races, for both speed and creativity.
MPR's Julie Siple talked with David Heintz about this year's milk carton boat.