Struggling to turn a delftship to maxsurf for testing

I've searched around for a good while, tried Rhino, Blender, some converter exe of sorts, all kinds of file formats.

Maxsurf can only import up to 12 meshes, which is very low, and I can't for the life of me get a perfectly normal STL file to be used as testing to see if the boat planes properly.

What could I be doing wrong? Also, Maxsurf Resistance is the correct one to try and make it go through water? I seem to have to start from Modeler and transfer over to Resistance through the programs to make it work properly, but can't get the files to work at all.

 

The Maxsurf test version only allows working with 12 surfaces which, for a simple hull, is usually sufficient. The professional version has practically no limit in terms of the number of surfaces. Try to reduce the number of surfaces. Work them in Rhino and export them to Maxsurf. Both are perfectly compatible. On the other hand, Maxsurf is a very reliable program for all the studies that you want to do.
If we could see what your boat is like, perhaps we can give you more concrete advice.

 

Would be fun to try and build a stepped hull inshore center console, but I keep experimenting with ideas on how to make it as good as possible. I really love watching videos of Fjordling 17's hauling ***, a very small boat hitting over 70 knots with the right engine.

The genereal idea is a 20 footer with somewhere above 100 up to 150hp.

I want to see if the steps will make it stay in the water better without lifting early or porpoising etc, but I'd consider it solely for the fuel economy.

Note that this is the most basic hull shape possible without any added strakes, I'm going to try to emulate a SeaVeeZ hull if this makes it to reality.

Obviously I did some radical changes to the hull, don't have a plan or anything, the angle is 4.5 rear and 3 degrees middle step. Looks aggressive but would probably net decent fuel economy at cruise speed unless its pushing the nose down way too much.

 

It seems that with 4 surfaces a valid model for Maxsurf could be made. Do only half a hull and indicate in Maxsurf that the surfaces are symmetrical. Even if you do not place a surface for the transom, Maxsurf will close the hull. Do not place surfaces closing the gap between steps, Maxsurf will close them.
Steps should be made up of more horizontal planes, following the natural profile of the hull as much as possible.
I don't know if Delfship models are exportable to other CAD software. Try creating your model with Rhino.