"marklan" wrote in message
news:fXD0d.154674$9d6.89731@attbi_s54...
The America's cup race over a hundred years ago ended in accusations and
disputes.Lord Dunraven accused the Am Defender of having carried illegal
ballast which would have extended her water line and consequently given
her
greater speed-(taken from the book)
My question is: How is that?
Would n't the extended water line be more serface area in contact with the
water, there by slowing the boat down. By having a greater resistance..But
is that different with sail boats?


I'm not a yacht designer so tell me to be quiet if necessary, but I think
the greater influence to boat speed is water line length where hull speed is
proportional to the square root of the LWL. When your moving at hull speed
there is usually enough wind power to push the boat faster but you would
have to push the boat over the bow wave and this would take exponentially
more power. So you might be right about increased drag from a greater wetted
area if the boat was travelling at less than hull speed, but at less than
hull speed you probably would not be heeling as much.

Sniffinvinyl