The single rotation occurs over the entire duration of the ride experience (almost 4 minutes), so it is very slow. I believe the reasoning for the rotation has to do with the way the ride system functions and its ability to return to the "home" position (or its starting position), which also plays into starting up the attraction at the beginning of the day and resetting the ride after any sorts of ride stops. The specific reasoning was well above my pay grade at the time I was there.