Ric,
Of the several boats I have know both versions of... The shallow draft
version is usually withing a couple of hundred pounds of the deep keel
sister !! either way. Most designers don't want them to float on
different marks.

They may make the keel the same in a side view, but also do things like
add psuedo-wings (Big Thick Short hunks of lead) or go to a Sheel sort
if profile.

I also have a very interesting bit to add here. My boat has an
adjustable keel (actually a 700# dagger board on tackle). We run at
1.5-2ft, reach at 3.5ft and point at 5.5ft. If we try to go to weather
with the board at less than maximum draft, I can make the sails work
just fine and the seeming angle between tacks will not change, but the
instruments tell me that my course over ground to heading deviation is
three to five degrees more (this kills the wvc or vmg) than it should be.

Matt Colie S2-7.9 "Bonne Ide'e"
Lifelong Waterman, Licensed Mariner and Perpetual Sailor


Ric wrote:

Usually the draught keel version of a hull is ballasted more heavily than
the fin keel sister so that the righting moment is the same despite the
shorter lever between centre of bouyancy and centre of gravity. Draught keel
version is therefore also usually a bit slower (even on a reach) because
overall it is a heavier boat.

The higher centre of gravity of a draught keel hull can also sometimes make
for a slightly easier sea motion, because you are closer to the centre of
gravity of the boat than on a fin keeler.