be careful of the different names
A retractable keel is different than a swing keel, which is different from a centerboard.....True retractable keels are rare, especially on small boats. A retractable keel is a full fin keel, where the whole thing (usually made of iron) retracts straight up into a well in the hull and/or cabin. Because it involves lifting so much weight and needs a place to retract to, this type of arrangement is usually reserved for large exotic designs where there is sufficient space for all of the necessary machinery and storage.Swing keels are more typical on small boats. Catalina made the design popular on their 22's and 25's. With this design, most or all of the ballast is contained in a fin that pivots up and down. Advantages: makes the boat trailerable; gives flexibility of shallow draft. Disadvantages: in an accident, all of your ballast can be lost or swinging around under your boat; mechanical problems w/cables, cranks.Centerboard boats usually combine some type of shallow stub keel with a relatively light centerboard that swings like a swing keel. Examples: Oday 22, 23, 25; Rhodes 22. Advantages: good draft, internal ballast, usually sail more like fin keel boats than swing keel boats do; disadvantages: centerboard can stick, break, etc.All other things being equal, a boat with a swing keel or centerboard will not point as high and will be more tender than a true fin keel boat.