[C38] Deep keel - 6'9"

[les]

On Tue, 2011-06-07 at 10:53 -0400, Marci Brown wrote:
> I’m guessing that those of you on the west coast don’t have any issues
> with shallows. On the east coast however, it seems like my eyes are
> glued to the charts (instead of the water) too much of the time. While
> I love the way Checksy handles, her 6’9” draft makes it hard to relax!
> What percentage of the C38s were produced this way?  How many of you
> have the deep keel, and do you like them? 
> 
>  
> 
> Marci J. Brown
> 
> Check’s In The Mail
> 
>  
Hi, Marci,
	We have the deep keel on JACE, and we don't have too many issues here.
Most harbors have deep channels here, and the harbors themselves are
typically 14'(-2 to +8 tidal range typical) in Southern CA.  If you head
north from here, however, the tidal range changes, and some areas have
large sand bars outside the harbors, where I am sure the keel poses much
greater challenges.  

	The keel is of course part of the design, to  offset the leverage of
the high aspect sail plan of our boats.  Tall masts offer greater
leverage and deep keels tend to offset that.  If you look up the shoal
keel for our boats, it is several hundred pounds heavier to make up for
the loss of leverage.  To keep handling reasonable, this is probably a
compromise as our boats are designed to heel to about 12-15 degrees when
sailing at hull speed.  i.e. 10kts of wind, 30 degrees apparent
approximately.  The ultimate stability, where winds reach about 20kts,
with full sails up will produce considerably more heel, but can be
depowered by flattening the sails, and the offset of the deep keel helps
with that.  To make the shoal keel deal with this will require about 150
to 200 more pounds than probably the optimum light air weight.  Where a
designer makes this choice depends greatly on how he perceives boat load
in the typical use, what he decides for wind range and so forth.  Some
of it is "empirically determined", i.e. experience based from design
experience.  Which is one reason that some designers are highly
preferred for certain types of boats, they build mostly those boats, so
their designs have more experience designed into them.

	With all that said, I have done some braille navigation, and love it
when the bit I touch down on is mud rather than stone or coral.  But
with the long keel, leverage works here, too.  After touching down in
one of these events, the boat will certainly develop a grin rather than
a smile if the contact is heavy or speed high.  I recommend a haul out
or a diver check at a minimum after a heavy bout of finding ground.

Regards,
Les H