they won't
if it's stationary and gets a dousing of water then they will payout
if youdrive through it like a spaz because the guy in front did, they will look at it as a driver being a twat
if it was possible i'd show you the ammount of standing water down the road that gets 3 or 4 hero's stranded in it everyt ime it buckets down, most of them are mechanically fucked where the engines hydro lock, and if that'st he case then you won't get a penny from the insurance if that's what you are thinking
on the other hand, if you say you were driving through and it was raining, there is also some clause where you have to take avoiding action or soemthing complicated along those lines
if you are trying to ford a stream and the car gets stuck and washes away, then it won't be a problem, but just parking it up in a river will at the very least come out of your pocket