alas no multidimensionality, black holes, worm holes or anything of the like just good old solid physics to deliver the amazing feats of the OT.
Floating ''on'' water, buoyancy is one of the oldest principles. The Ark is a sealed gold box, that would float, so would any sealed box.
The box does not deliver the key miracles, but it does allow people to survive in a barren landscape by providing energy. The noted miracles were performed by the aten that sat on top of the box, propped up between the cherubs. That should be kept in a box unless it is being used.