Explore buoyancy and floating forces with this Building Boats STEM project for Grades 6–9. This hands-on design challenge investigates Archimedes’ Principle, density, and water displacement through an NGSS-aligned PBL activity.Students design, build, and test boats while analyzing how shape, materials, and mass affect buoyancy and stability. Through experimentation, measurement, and structured worksheets, learners develop a clear understanding of floating, sinking, and fluid forces. With printab