First of all, even if someone did drill a hole at the bottom of a destroyer, the water could not have filled the chamber, since the air pressure would have stop the water. Secondly, even if the chamber were filled with water, the depth charge could not have been detonated. Unless the whole destroyer had sunk into the deep water. No matter how much the water filled the chamber, the pressure could not be bigger than the submerged depth of ship, which was not enough to detonate depth charge, not even close.