Designing a hovercraft from scratch has to be one of the most difficult things you could do!
Unfortunately the odds of a new design working successfully are extremely low - even when designed by a professional engineer! The main reason is the wide combination of engineering disciplines and knowledge required to achieve a working design (mechanical, electrical, pneumatics, aerodynamics, hydrodynamics and power transmission to name but a few!).
The buttons above link to our unique range of tools and software which will assist in both designing a hovercraft and servicing/maintenance. If you intend to design from scratch then we would strongly recommend first using our world-class performance calculator - it should ensure that the fundamentals of the design are good enough to guarantee it will actually work!
There is a wealth of knowledge and experience available from the members of the HoverClub - if you have questions please ask and someone will almost certainly have and answer.
Good luck!