Adding weight presents the problem of needing to add "horsepower" to get the additional weight up to speed.
Then of course you have the problem with the additional weight causing the boat to sit lower in the water so you have to add even more sail area.... its a viscious circle that results in something that looks a lot like....................... Playstation.

It seem like I heard that the initial design of Playstation had a tendancy to pitchople, so they added like 25 feet to the bows to add bouyancy. Soooooo, My guess is that rather than adding weight to the back of the boat the more effective solution is to add bouyancy to the front of the boat. which lengthens the waterline which changes the calculations of the "hull speed limit"
O Gawd, my head is beginning to hurt. <img src="http://www.catsailor.com/forums/images/graemlins/crazy.gif" alt="" />

Stephen