BPY sixth grade science class just completed their unit on the metric system with a float down the river. Students had been learning how to calculate density and compare densities of different substances. Students then discovered buoyancy and discussed how materials float and compared floating objects in different liquids. They compared an egg in freshwater with an egg in salt water. Then, the students were tasked with designing, building and testing a boat that can withstand a trip down BPY’s backyard river. After the boats were completed, students put on their boots and went into the river to watch them set sail.