Gone with the Wind     In this design, you are to test how the shape of a sail effects the speed of how fast a boat can go.  To make the test more accurate, you should use actual sail material if you can get a hold of it.  Then use a fan, a boat (any size or shape), and a contained area to test your project.  I do not recommend testing in an open area like a pond or a lake.  A bath tub or even a container filled with water will work.  To make your project more accurate, do not change your boat or anything but your sail between each test.