On Thu, 3 Jun 2004 12:06:33 -0700, "Gordon"
wrote:
Yes but the real gain in effiency comes from the fact that the pitch on
the blade on one side now more closely equals the pitch on the opposite
side. This also means it takes less rudder to maintain a straight line and
therefore less drag.

==========================================

This sounds like it ends up closing the loop on the "prop walk"
discussion and starting around the mullberry bush again. We pretty
well established that boats with horizontal shafts had just as much
prop walk as those with angled shafts.

My guess is that it all comes down to a resolution of force vectors in
the vertical and horizontal plane, using shaft angle with the bottom
of the boat as the vector direction.