The problem with swing keels, vs center board
boats, is all the ballast is in that big swinging plate with a swing keel. In a knockdown, the board can swing back up and the boat will no longer have positive stability. The could leave you with the
mast pointing down and the part of your boat that should never see the sun blinded by the light. Multiple deaths from a swing keeler that turned turtle in
San Diego Bay last year.
Center board boats have smallish keel and a largely unweighted board. The board does not act as ballast. When it's down, it adds additional resistance to sideways motion for better windward performance.
Keel boats come in all sorts of configuations and keel depths.
Racing boats will have a deeper, shorter keel. More cruising oriented boats will tend to have shallower, longer keels. The deeper the keel, the more resistance to healing and better able to stand up to more sail area in stronger winds. A blessing for the
racer, not so much so for the cruiser.
What really will determine what you need is the launch ramps in your area. If they get deep quickly,
full keel boats are easy to launch with an extendable tongue or even a
rope to get the boat and trailer into deeper water. If the launch ramps are shallow, you'll be forced to go with a
shallow draft fixed keel, centerboarder, or swing keel. That is if there are no lifts in your area. Most of the Yacht clubs on the Alameda Estuary have simple permanent cranes for launching keel boats up to around 30' length and 6' plus
draft. The boats are built with a
lift ring so it's just a matter of hooking to the crane, hoisting the boat out, and swingine it onto it's trailer. BTW, by crane, I'm talking about a simple inverted L shaped beam with a chain hoist, not some Bucyrus Erie behemoth.