You can hover through the air at your normal Move rating. You are very agile in the air, and can stand still, move straight up or down, and otherwise move just as if you were walking.
Calculating movement in three dimensions is somewhat different from normal. Downward movement if free. Movement upwards counts normal, but lateral and vertical movement is calculated separately and added together to figure effective distance. So if you move to a point five meters away and three meters up, you have effectively moved eight meters.
This schtick is related to Flight and your flight speed will improve if you take that schtick several times.