Like this guy said, there are multiple options, actually 5, per rule 806.02.D:

A player whose disc is out-of-bounds receives one penalty throw. The player may play the next throw from:

-The previous lie; or, -A lie designated by a marker disc placed on the playing surface at any point on a one-meter line that is perpendicular to the out-of-bounds line at the point where the disc was last in-bounds; or, -If a perpendicular lie as described above is not available, a lie designated by a marker disc placed on the playing surface at the point that is nearest to where the disc was last in-bounds, and that is up to one meter away from any out-of-bounds area.

The above options for an out-of-bounds area may be limited by the Director only with prior approval from the PDGA Tour Manager. At the Director's discretion, the player may additionally choose to play the next throw from:

-Within the designated drop zone; or, -A lie designated by a marker disc placed on the playing surface at any point on a one-meter line that is perpendicular to the out-of-bounds line at the point that is nearest to the position of the disc.