Full ride video showed the ride as 5:50. Not loading, not waiting. Boat is moving 5:50.
The first full ride video that was posted (and quickly taken down) was about a minute shorter than this, so clearly the ride time is variable.
EDIT: That first video, from Attractions Magazine, seems to be back up and does show a roughly 5 minute ride time.
EDIT AGAIN: I just watched the Blog Mickey video - the difference is largely a PoC-style boat logjam at the end of the video. Besides that, both videos show a ride time right around 5 minutes.