Ron,I have a 35' swing keel sailboat the model is named Clearwater and it was built by Holby Marine in Bristol, RI back in the late 80's and early 90's. They only made 7 of the 35' version, there was also a 45' version.
The keel is nearly 4,000 lbs of lead and it swings almost entirely up into the central salon area (there is an 8" wide water tight trunk that divides the salon in two). With the keel up (the rudder also kicks up) the boat draws 1'10" (you read that right) and with it down about 6'. The original owner had it commissioned to explore the many small creeks and rivers along the coast in Maine. We purchased the boat last year for use in North Carolina where we live on a creek that can get pretty shallow (2-3') depending on how the winds blows.
I have only had the boat a year and so my experience is limited. The keel is raised using a 2 speed winch on the cabin top. It takes some effort that could be reduced if that winch were electric. The boat is designed to sail with the keel at any position, but you do sacrifice leeway with it up. Dropping the keel definitely stabilizes the boat and makes heading to wind possible. Downwind it runs fast with the keel up. And it motors well with keel up as well.
this is what the keel looks like partially raised. It has a foil shape, so it provides the forces of a full keel. I have no problem with barnacles as the keel fits the slot tight and is self cleaning when lowering (4,000 lbs removes anything in its path)
The keel will swing up if you should run aground on something hard. There is a hydraulic system that prevents the keel from just dropping back down after going over an obstacle. The PO found out the hard way that when the keel just drops it puts too much strain on the keel pin and other structures. So the hydraulics were added to slowly lower the keel from any raised position.
There are modern manufacturers that make similar designs (Southerly of the UK is one).
We are very happy with this boat, we could not have this size boat in our creek without the swing keel (except for cats of course).
I'm glad you posted to this thread. When I read Denise's question, I immediately thought of your boat.
Would you be willing to post up some interior photos again? I thought the way they integrated the swing keel trunk into the cabin space made for an interesting layout, showing that a little unconventional thinking can create some clever solutions.
Denise, I shy away from moving parts in my keel systems, but for coastal shallow estuary sailing (chesapeake, etc) they really do make a lot of sense.