I have just a basic fin and a skeg hung rudder.
My dream is a Southerly with a lifting keel. The ability to explore with one of those would be smashing.
My Clearwater 35 has a weighted swing keel, like the Southerlys, but it also has a swing rudder. With the “landing gear” retracted, as shown in the thumbnail, the draft is 2 ft. With the keel down, the draft is 6 ft and the rudder draft is about 3’ 10”.
This boat has inboard shrouds, allowing tighter genoa sheeting angles, and with the elliptical keel, she goes to weather with the best of them. This boat is not tender, due to form stability, weight discipline in the design, and 5000 lbs of lead ballast. Half of the ballast is glassed into the slack bilge and the other half is encapsulated in the leading edge of the keel.
The headroom under the coach roof is 6’3”, but the keel trunk goes all the way up to the coach roof, splitting the main cabin.
So, there are some compromises in the design—primarily in the location and size of the keel trunk, but the advantages of variable, shoal draft are downright addictive. Harbors are larger, shortcuts are available, and gunkholing options are greater than with the traditional 35 footers.