Doug Lord: Single Asymmetric Curved Daggerboard
This board, at the very least would permit vertical lift to be developed along with lateral resistance. If the lift function was not needed in light conditions the board could be retracted enough to just allow lateral resistance.
The board moves side to side in a partially open continuous, curved trunk.
Different versions might allow full flying though the characteristics similar to surface piercing foils and altitude control would have to be researched a lot more.
see thread for details:
Posted by: Doug Lord - website: https://www.sailwolffoiler.com/wolf/