The purpose of this article is to describe a simple laboratory activity in which students collect a series of measurements and then use graphical analysis to determine the nature of the relationship between an object's mass and the volume of water it displaces. In this activity, students explore the relationships between the mass of a floating object, the amount the object sinks in the water, and its displaced volume. The data will reveal a unique relationship between an object's metrically measured mass and volume and its buoyancy in water. This can lead to an elaboration of the density concept and provide a concrete model for systems involving other forms of balance and equilibrium. (Contains 5 figures.)