I've been looking at some of the spells in TME that makes stuff fly.
Both the Woolen Steed of Araby and the Vessel of the Clouds add +1 magnitude for unsupported surface.
Is the purpose to allow the carpet or boat to fly further up in the air than the e.g. the 6 feet above ground of the Unseen Porter and over over water (as opposed to solid ground) or is it something else I just don't understand?