Jim,

I'll take a crack at it.

I have a Gulf 29, with a wing keel. The wing give you right force for
less keel length. As you heel over the wing provide a righting force; by
the position of the wing. The Wing produces lift. When it is heeled,
that lift on the lower (deeper heeled) wing has the advantage of
leverage and give and additional "righting force" to the keel.

It also produces a damping effect against hull pounding.

It is important to have flow over the keel to have it work or it is just
added "Wetted Surface" but with the keel working you get the added
advantage of sail area in a more vertical position for more driving
force

There are attached pictures in Pneuma's Page in the signature below.
Hope I've helped. Jim, there is a difference between a wing and
winglets. A wing has a aileron shape to it to provide "Lift" winglets
are basically to shed the turbulence at the bottom of the keel




http://community.webtv.net/tassail/ThomsPage

http://community.webtv.net/tassail/Pneuma

Two notes about wing keels, based on experience with a Hunter 35 in the
Bahamas about 15 years ago:

Anchor rode will wrap around the keel when wind shifts significantly at
anchor, especially in shallow water. You may have to dive in to unwrap it.

Fording a shallow sand bar may become impossible. Where a fin will dig
a narrow furrow and allow you to continue, the wing will have a very wide
footprint and turn into a plow. Even heeling the boat does no good, since
the lee wing will dig deeper.

--

"Thom Stewart" wrote...
Jim,

I'll take a crack at it.

I have a Gulf 29, with a wing keel. The wing give you right force for
less keel length. As you heel over the wing provide a righting force; by
the position of the wing. The Wing produces lift. When it is heeled,
that lift on the lower (deeper heeled) wing has the advantage of
leverage and give and additional "righting force" to the keel.

It also produces a damping effect against hull pounding.

It is important to have flow over the keel to have it work or it is just
added "Wetted Surface" but with the keel working you get the added
advantage of sail area in a more vertical position for more driving
force

There are attached pictures in Pneuma's Page in the signature below.
Hope I've helped. Jim, there is a difference between a wing and
winglets. A wing has a aileron shape to it to provide "Lift" winglets
are basically to shed the turbulence at the bottom of the keel




http://community.webtv.net/tassail/ThomsPage

http://community.webtv.net/tassail/Pneuma