Maxsurf stability - Model requirements

Hi Everyone,

Please can someone outline the basic requirements of 3d models  used for stability and hydrostatics in Maxsurf?

It should be NURBs - .IGES with one closed surface?

how complex can the model be?

can it take other file formats like ,obj or mesh?

Sorry if this is a very basic question I am new to the software and have not yet found where these questions are answered in the documentation if you could direct me I would be most grateful.

Many thanks,