Originally Posted by
Conway
While it does seem a little Deus Ex, but in practice it's easily explainable. First because it's water he can't use actual ground as a Ground like an electric fence because he would have been shocked too. If you think about the thing as more of a stun gun then: If Batman's suit is the battery, and his fingertips the contact points then yes when the fingertips were exposed the water would have arced the voltage and stunned him too. However if he had pressure switches in the gloves then the current wouldn't have been released until he gripped the tentacle hard enough to trip the switches. The problem with that is he would have to have used both hand on opposite sides of the creature's heart or brain to have any real effect. Otherwise it would have been isolated to just the area he touched like a 9volt battery on your tongue.