Not sure what you mean. If you're looking for someone to run shuttle with, you can usually pick up a ride from the takeout back to the put-in by asking around or hitchiking. If you're referring to the act of kayaking as "riding down the river" then it sounds like you are a complete novice and should sign up for lessons and work your way up to a Class III run like Brown's. Even at low water, a novice would unprepared for the challenges posed by Brown's.
Good luck,
-AH