There are some obvious precautions to driving in the rain, like slow down, turn on your headlights, turn on your wipers, and possibly turn on your defogger.  Not so obvious are things like a rear fog light.  On later model Porsches the fog light(s) indicator is on the lower left side of the surrounding bezel.  This is only an indicator that the light(s) is (are) on, not a position for the light switch.
Current Porsches have low beams that are quite capable of penetrating the fog and have eliminated the need for separate fog lights.  Slightly older Porsches have separate front fog lights and a single rear fog light on the driver's side of the vehicle.  By pulling the light switch out one click, the front fog lights are activated.  By pulling the light switch out another click, both the front fog lights and rear fog light are now activated.  The newer Porsches have only the rear fog light requiring one click.
The rear fog light shines brighter than the tail lights.  Because it marks the driver's side only (for faster cars approaching quickly from the rear on the Autobahn), be prepared for the uninitiated to inform you that you have a light out on the passenger's side.  When watching trip videos, the rear fog light does stand out as intended.
Now for dealing with deeper water and hydroplaning.  A Porsche will do an excellent job of communicating the relationship between the tire contact patch and the pavement.  When contact begins to diminish, you should be able to distinguish the difference.  At this point the tire can no longer channel the water quickly enough to keep the tire on the pavement.  By lifting off the accelerator and slowing the vehicle, the tire will regain its grip.
The other approach is to keep your speed and give your tires less water to deal with.  How?  Most roads have grooves worn into the lanes by heavy trucks.  By moving one side of your Porsche toward the middle of the lane and the other either toward the inside or outside, you should be running on higher ground.  This is particularly true of older highways that have seen plenty of traffic.  Do your best to maintain contact and be respectful of differentiation of speed.  Stay safe.