Car knocking

I recently dove through a large puddle of water and my car stalled out when the water splashed on it. When the car finally started back up it had a really loud knocking sound to it. I have checked the ignition and oil for water. I see no signs of water that got in the engine anywhere. the faster the car goes the quieter the noise gets and the slower or at stand still the noise is unbelievable. Can anyone explain what has happend and how i go about fixing the problem

What kind of car? Check Engine Light on?
Is the vehicle running fine other than the noise?

Offhand, I might say the knock sound is a severe engine miss due to water on secondary ignition parts.

If the vehicle is running badly then be aware that your continued driving is just creating more problems.