One recovery method is to secure the target object to a line deployed from the boat and have it pulled up from the surface.
If the object is lightweight, place it in a mesh bag underwater and attach a rope with a hook from the boat to lift it safely to the surface.
If the recovery object is heavy or large, create loops at both ends of the rope. Pass one loop through the other to form a large sliding loop, wrap it securely around the object, and then lift it using a winch on the boat.
