We're having a bit of a rainy season here in the UK at the moment and whilst watching the following local news report I noticed a Prius had become stuck in a flood on a local road. BBC News - North Yorkshire floods cause severe disruption And this got me thinking. Surely so long as the flood isn't too deep that it comes in through the bottom of your door and you don't have to go too far, then wouldn't you be ok switching to EV if your engine stalls? Even if the engine doesn't stall, wouldn't you be better just selecting EV and driving slowly through the flood, then when you get to the other side, just allow the car to drain a little and then set off again? So that Prius in the news report should have just selected EV and slowly driven out of trouble? (the water isn't over their wheels)
I would not be planning on what to do if the engine stalls due to high water. I would plan how I would not get caught in that situation. I have driven our Prius (2010) thorough heavy downpours a few times. It hasn't had even a stumble and seems to handle water-covered roads very well with not even a hint of hydroplaning. I don't know if that is because of the high pressure in the tires (40 psi) or the weight distribution of the vehicle, but it is very secure on wet roads. Of course I don't drive at excessive speeds.
There is a local campaign here: "Turn around, don't drown." Every year someone dies trying to drive through flooded roadways. EV or SUV, just DON'T do it.
That would have been the best choice, in my opinion. Supposedly the Prius, being highly electric, is well sealed. Point in case - I've read elsewhere on the forums that washing the engine doesn't have any adverse effects due to the complete seal on electric components. So, provided the battery still had a charge the driver could have selected EV and pulled out. It would of course kill the battery quickly as moving water takes a ton of energy, but it was a possibility.