Two things come to mind, the first structural, the second hydrodynamic.

I don't know about the boat you're looking at (Morgan 46?), but
most boats have floors for carrying the keel loads, or else they
are bolted to the bottom of a sump (or maybe encapsulated).
Regardless of whatever attachment method is used, the
righting moment is increased, and the load has to get carried to
the hull. For most overbuilt cruising hulls, this may not be an
issue but if the laminate is sized exactly for the original righting
moment you may develop trouble.

Hydrodynamically, the lift you create from the keel is pretty
much a function of span - adding a bulb will reduce the
span by that amount. If the boat is tender the tradeoff may
be worth it - if it's not then you may actually lose windward
performance because you have a less effective keel and you
are dragging around all that extra weight. If you plan
on doing a lot of racing or windward passages then the
extra righting moment may be worth it, but probably only
if you consider the boat tender to begin with. Think about
whether the boat will spend a lot of time fully powered up
going to windward or whether youre likely to back off
and take it easy when headed to the next destination.

Matt

"Skip Gundlach" wrote in
message ink.net...
So, we're looking at boats, and Henry Scheel comes to light. He's
patented
a keel that several manufacturers are paying royalties to use, and what I
read suggest that rigorous tank testing holds out the superiority to
straight keels, so, presumably, it must be worth *something*...

However, just a Henry Scheel design does not a Scheel keel include. Too
bad...

For those not familiar, it's got some of the attributes of a wing and some
of a bulb, but primarily greatly increases holding power and reduces
vortex
drag over that of a standard keel, particularly beneficial to a shoal draf
t
need, without the anchor-digging-in attributes of a wing.

So, the boats I'm looking at don't have this keel. I've read of those
cutting off the bottom of a straight keel and adding a bulb, or
equivalent,
to achieve a shoal draft with the same equivalent weight. They've done
this
perhaps by somehow attaching at the bottom, or, as one site I discovered,
bolting two lead halves to the remaining keel, forming sort of a bulb
wing.

Now to the question. Have any of you done, or know someone who has, an
addition of such a bulb/wing to an *existing* - not shortened - keel?
The
benefits I'd see are better holding, and more ballast, as low as possible,
against a minimal overall increase in weight (projected is from 30000 to
maybe 32/33000 pounds displacement, with that increase also applying to
the
current 8400# ballast, light by my thought).

I'm more interested in experience stories, if there are any, or
engineering
reasons for or against, as opposed to 'I think it would...' information.

Thanks.

L8R

Skip (and Lydia)


--
"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away
from the safe harbor. Catch the trade winds in your sails. Explore. Dream.
Discover." - Mark Twain