The design criteria were:
Fairly small - I wanted something that would be easy to find space to run (eg, in a car-park or on a limited area of beach) - I didn't want it to be difficult to find somewhere to run it.
Fairly cheap - I didn't want to spend hundreds of pounds (but I have, eventually, because in the development of Mk1 and 2 I bought a new R/C set, and a fancy charger, and some new battery packs, and more expensive fans, plus some tools (but you can't begrudge buying tools - that hardly counts as spending money)).
Electric (for ease-of-use, and it also makes it easier to find somewhere to run if it's fairly quiet and doesn't chuck out clouds of oily smoke).
A hovercraft is an amphibious vehicle that is supported by a cushion of slightly pressurized air. Although often seen as a mysterious, even bizarre mode of transportation, it is conceptually quite simple.