Originally Posted by CapnBilll
Good point, heavier doesn't mean slower we all have the same speed limit. It just means you have to carry more sail to go same speed at same wind speed, but...a heavier keel means you can.
Not exactly. Hull speed of a displacement boat is theoretical and can be exceeded if there is enough power to do so - either sail power or engine power. In lighter winds some boats can't reach hull speed because their sail area is too small for the conditions - this is common on some heavier designs. In heavier winds if they can't stand up to their sail area they may not achieve it either. This depends on stability, which comes from the keel as well as form stability of the hull. A wide flatter bottom will mean more stability before the angle of heel required for the keel to have much effect.
There are boats that sail well in a very narrow wind range. They do not move well in light air and can't stand up to the canvas needed in a blow.