The Volt has an ICE too, so will have similar restrictions if the gas engine is running, it has to breath.
Electric vehicles in general are better in water since they don't have to breath. Water naturally does not conduct electricity well, distilled water has very high resistance, but salty water will be lower, so even if the battery is submerged it could likely operate. However, as any modern car, it might take damage to electronics over time.
People, electricity, and water don't mix because the use case in a house is a bathtub with an appliance can give the electricity a path to ground from the wet appliance through the human to grounded copper pipes. It only takes like 150 milliamps to kill a person. I think generally accepted value is 100 to 200 mA. In an electric car there should be no path through the human to ground unless you are tampering with the wiring.
Volt in water:
That is a non operational car, but pretty sure they did an operational test as well, but can't find the video.