The skirt on a hovercraft is the part which stores the cushion of air and allows the vehicle to hover. On any hovercraft, including remote controlled, or RC, hovercrafts, this is the critical part. So, if you are building your own homemade hovercraft, or replacing the damaged skirt on an existing hovercraft, there is a simple way to build it. The best material is a simple polythene sheet, but you must make sure there are no holes in the sheet.
Lay out the polythene sheet on your work surface and place your model hovercraft on top of it. Verify that there are no rips, tears or holes on the sheet.
Trace the outermost edge of the hovercraft body onto the sheet. Your hovercraft should have a vented section on the bottom, which the craft stands on. Trace the outside edge of this section as well.
Measure the height from your work surface to the top of the skirt cover. This is the section of the model which is directly on top of the skirt. Multiply this number by two, and add 1 inch for the seams. This will be the width of your skirt pattern. For example, if your model is 3 inches from the bottom to the inside, multiply it by two and add 1 for a total of 7.
Draw a second outline of the skirt pattern, moved out by the distance you calculated. If your total was 7 inches, measure 7 inches from the sides of the model and trace a second line at that point.
Cut out the outermost line from the sheet, and discard the excess. Cut also the innermost outline of your hovercraft and discard the small shape so you have a doughnut shape which matches the base of your hovercraft.
Place the vehicle over the centre hole on your skirt pattern and fold the left and right sides up, then the front and back edges. Make sure the outer edge of the skirt fits the model. If your hovercraft has any right angles on the design, you will form a flap of the skirt material. Mark this flap.
Unfold the skirt and trim where necessary so that your hovercraft's skirt fits properly.
Tape the outer edge of the skirt to the underside of the model so that it fits beneath the cover. If you have a right-angled corner, cover the original flap with duct tape to create an airtight seal.
Power on your hovercraft and test that the skirt functions properly. It should fill with air and lift the hovercraft off the ground. If it does not, consult your original hovercraft model plans, and check the skirt for any leaks.