The fin's function can be transferred to a surface piercing cavitating inclined plane
I am not an expert in this field or in any field.
Here is my non expert reading of it.
The 'box' is bounded by the limitations.
The fin limits the board to speeds below 50 knots.
'The fin's function can be transferred to a surface piercing cavitating inclined plane'
Fins are vertical and stop work when they cavitate.
The article seems to suggest that an inclined cavitating surface could provide a opposing force (lift) better than a vertical cavitating fin.
Have I missed something?