If your vehicle begins Hydroplaning you should?

Ease the throttle.

If in a car, grip the wheel firmly, to prevent it being pulled out of your grasp.

In a boat, ease off on the power by approx ten percent to prevent the engine from over-revving.

In a plane, pull back on the yoke if preparing for take-off; if ready to land and you're not in a spruce goose, bend down, place your head between your knees, and kiss your @$$ goodbye