A hydro lock is when water gets into the engine and destroys it. It could be that or something else. The easiest way to see if it is hydro locked is to open the hood, and open the engine air filter compartment and see if there is water in there. If there is water inside the air filter, then most likely your engine hydro locked and is toast and you need a new one. If its bone dry, come back. But what does the car do when you try and start it?