With regards aquaplaning speeds, bear in mind these numbers are not to be used in a scientific manner. Merely guidance.
But also to note, these 8.7 times figures (i.e. 9 times as the rough guide) are for a wheel that is already rotating. These speeds can be reduced to, in some cases, around 7.5 times for a stationary wheel. Hence the recommended Boeing technique on a wet/contaminated runway is for a firm touchdown to help increase the friction required to spin the wheel up (also the excuse I use on dry runways for my landings. "Sorry girls, Boeing recommended landing"..... :-) ).