Quite evidently the next step in the process for our hovercraft was the placement, number, and size of ventilation holes. We knew we needed ventilation holes, without them the thin plastic skirt would surely burst due to pressure build up. Also, without a place for the air to escape, the hovercraft could not truly hover. Another factor that played into the placement of the ventilation holes was that the holes needed to be placed relatively close to the center bolt. This would allow the air to escape, forming a pressure bubble inside the ‘doughnut,’ essentially creating the ‘doughnut hole.’ The resulting air pressure buildup in the ‘doughnut hole’ would leave one place for the air to escape, underneath the hovercraft, thus creating the hovering ability. Therefore 12 one and a half-inch holes were cut into the plastic, all six inches from the center bolt.
The hovercraft was then attached to a shop-vacuum and inflated. We allowed one person on to test the abilities of the hovercraft. The person was indeed hovering; air was rushing out from underneath. Another indicator of the hovering ability was the reduction of kinetic friction.