Dynamic - high speeds, standing water
Viscous - lower speeds, smooth surface, thin film of water
Reverted rubber - locked wheels
The formulae I learned were slightly differnt than quoted above, so:
7.7 * sqrt (tire pressure) for a non-rotating tire (i.e. during landing)
9.0 * sqrt (tire pressure) for a rotating tire (i.e. during take-off)
Was it an American interview? The Americans LOVE hydroplaning questions.