What is your car doing when the tires are literally riding on top of water on the street?

I always thought it was aquaplaning. Or is that just here in the UK?

I live in the U.S. and I have always heard of it as hydroplaning.

ATS, I thought that, too

This can be very scary, it is important to keep your tyres in good condition.

ATS, you are correct ATS but as hydro and aqua both refer to water who cares

The "road sailing" choice is pretty funny.

ATS, Me too, ( if I can still say that) , hydroplaning is what happens when a boat fitted with hydrofoils attains the necessary speed and lifts itself up.

JoeJ., Interesting point to make, is don't utilise your cruise control under such conditions, it confuses the system and results in potential life threatening conditions.