To perform this activity as a class, the following materials are needed:

• clear bucket filled with water
• toy boat (alternatives: reusable storage containers of various shapes and sizes, or make a boat using available classroom or household materials)
• large rock (or an equivalent object of varying size and weight; a good option is a metal weight used in kinetics or other physics activities)
• sticky notes and a pen, to mark water levels
• 3 or more large poster-sized sheets of paper
• pens or markers, for writing on the poster-sized papers
• Rock and Boat Worksheet, one per student