In this article, the authors discuss a unique and challenging laboratory exercise called, the paint-stir-stick submarine, that keeps the students enthralled. The paint-stir-stick submarine fits beautifully with the National Science Education Standards Physical Science Content Standard B, and with the California state science standards for physical science, which state that the student will know how to predict whether an object will float or sink (8d); that the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid it has displaced (8c); and when the forces on an object are balanced, the motion of the object does not change (2c). This hands-on experience in building a submarine allows the students to learn about buoyancy, buoyant force, Archimedes' principle, and motion in an active engaging manner. (Contains 2 figures.)