This is one GE I did earlier - at least a young guy in Missouri is building my design for a solar powered ground effect boat.  He initially built a 1/6th scale to see what it would do:

The model is overpowered in scale.  In full scale it will carry 2.2kW of solar panels.  That will get it to about 16mph.  With wing extensions covered with more panels to get total to 4kW it should achieve sufficient ground effect lift at high L/D to get 30mph.   The design does not have a tail plane to achieve pitch stability so he will need care pushing into the wind.

A key issue with GE on a sailing boat is that the apparent wind is not from the front although the greater the efficiency the higher it will be to the apparent wind.  What matters is the efficiency of the lift in terms of L/D.  If the L/D is no better than the foils then GE has no benefit.   It would be better to have two wing beams with no enclosing mesh rather than one large wing beam.  The boat would be controlled from a cockpit on the ww hull.  At rest the meash deck could be rolled out. 

With regard to flying proa, the ideas from sail rocket have potential for development.  I have played around with a 1/5th scale model of a beach proa with a canted sail.  It has gone through a few iterations and will literally fly although uncontrollably with the limitation of only steering and boom swing controls:

The concept here is to get both lift and drive from a single canted sail. 

On the model the sheet control is limited so the sail cant had to be set for the conditions with a view to get the best balance of lift and drive.  In full scale with sheet control, releasing both sheets allows the sail to completely feather by flying horizontally. 

A high aspect sail will give better lift to drag than foils at high speed where cavitation becomes a challenge.  Hence why canted sails are interesting.

Similarly a kite offers the opportunity for vertical lift without heeling moment however the L/D of kites is not quite as good as foils, at least till cavitation has to be managed.  

This is another GE boat I have played around with:

A friend built this with high hopes but after testing I realised it did not have the power to get enough planing speed to get substantial air lift.  The orange one linked above was the result of some calculations rather than just a nice looking shape.

And then there is an air lift boat I played around with a view to get the yellow one on a lower drag starting platform:

I played around with the air lift idea in a number of variants up to human scale before I got to grips with the various limitations. It works well for a high power to weight craft that can get stuck at planing speed before air lift.

Rick

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