If you take the time to go to the Pro am site and read the rules I believe you will have your answer.
16. Pro Division Definition: Any Captain or team member, excluding the observer, who is/was (or has been within the past 5 years) a licensed charter boat captain, fishing guide, or commercial fisherman, is required to enter the Pro Division. All others may enter the Amateur Division. Amateurs may enter the Pro Division if openings are available.