It looks like the shear tip of the NP Z1 was designed so that it is for
the most part parellel to the air flow when the sail is raked.
I wonder how important the tip being parrellel to the wind flow is. The
NP web site gives a bunch of reasons why the tip is wonderful and the
parellel wind flow isnt mentioned. It would seem that the sail being
very upright would still have the benifits even though the end of the
'tip' at the leech would be higher than the end of the 'tip' at the