The job you're doing is not about dry docks, but a yacht harbour. The place the boats are kept when out of the water is called the yard or the hard or hard standing. This is because the land is harder than the water. If you observe the shape of the various craft you'll see some, while boat shaped, are reasonably flat (the dread motor boats or "batidoras" as they are known to the sailing fraternity, and that depend on thrust and speed for their seagoing qualities) others (old-fashioned sailing boats) shaped like a wine glass using keel shape and weight for stability and sailing qualities. Between these two extremities exists an entire universe of forms. All these need supporting in the yard or on the hard. If not they'd tipple over. therefore, there are cradles shaped for motor boats and others shaped for sailing vessels. These cradles are robust, cubic or oblong kind of structures of wood whose upper profile is "V" shaped –shallow for motors boats, deep for boats with a keel. The difference in the infinite hull forms is compensated with wedges, odd bits of timber and what-not. One-off regatta boats often have a purpose built cradle that they nestle into. Most sailing boats are not put into a cradle, but are chocked, as I mentioned in an earlier entry… Chocks are lengths of timber, also known as props. Generally on either side of the vessel, about amidships, the yardhands, dockhands/bosuns/boatswains/ marina staff/hands place trestles, which you might describe as a short section of a cradle, but whose length is straight and not curved to fiat any particular kind of vessel.
Below you can see examples of cradles for transporting boats. The cradles on the hard are much shorter, the trestles shorter still and go one to each side.

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Note added at 31 mins (2010-11-28 15:26:08 GMT)
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Apuntalamiento: Propping/chocking/shoring. Prop/chock/shore.
A dry dock is a dock after the water has been pumped out. This is only used for really big boats. At Barcelona harbour, even the luxury yachts are hoisted out and shored/propped/chocked