A pivot turn is a technique for turning a boat 180` in a narrow channel. The turn must be done in the direction of the propeller's prop walk when the boat is geared in reverse.
The timing of the turn relies on a number of factors. Most importantly, the wind, the current and the width of the channel you're backing into. If the channel is narrow, you may need to turn the boat before the bow has fully cleared the slip.
If either the wind is blowing, or the current flowing, you'll want to stay on the near side of the channel. Power ahead away from the dock at a shallow angle.