I will leave the centreboard for cruising boats aside for a while. Very popular in France, built by a few shipyards and in aluminum, the model is known as "deriveur integral". True centreboarder often ballasted, the raised board is totally integrated within the shape of the hull.
The Swing keel is always outside the body, in a retracted or extended position, whether up or down and with only its articulation inside the hull. The keel shape results in a high aspect ratio foil.