What Floats Your Boat?

This open-ended boat building exercise is meant to be part of a three-lesson series on ships. Links to the other two lessons are included. This particular part is mostly a group lab activity in which they build a boat, find its load line in both fresh and salt water, and measure the water displacement when filled to the load line. Because of the applications to Archimedes' principle, this may best be suited to upper elementary children.