Come guy's weight in on the question of the day.
Now with a water capacitor instead of actually changing the distance between the plates, we can say the water is actually part of the plates. If we remove a portion of the water, we are in effect widening the plates and the capacity of the water capacitor is actually going down as more water is removed. We hit a physical limit when all the water is removed, since the metallic portion of the plates are fixed in position.
On the other side of this limit is when the plates are fully saturated with water. We can say the plates are so close together, they appear to be shorted. Hmmm... But like a spark gap, shorting is only a factor of the voltage applied. At one volt, no short, but at two volts or higher, we arc across the gap. We now see what for all practical purposes looks like a dead short, but it actually isn't, it's just a very tiny gap, one that only requires two volts to arc across. So when the water capacitor is saturated with water, the capacity is at a maximum. This maximum is set by the atomic arrangement of the water itself. You physically cannot get the water molecules to pack themselves any closer together and decrease the distance between the plates or the water as an extension of the metallic plates.
Am I getting close Ronnie?