When you're at the main complex you will see hundreds of scouts for the 17u and 18u tourneys.
When you're away, I think you can expect 15-25 scouts to come to your games IF your players are of sufficient quality AND they do their homework to communicate with teams of interest.
Which points out two keys to success:
1. Get onto the best team that will let you play. The better your team, the more scouts will follow your team, the more scouts will see you. Don't make the mistake of taking the team your dad started because he wanted you to be the star of your team.
2. Communicating with scouts is something a player should be pro-active about. If your son is 15, or maybe considered 16u by now, this year may be more of a learning experience for him, also a chance for PG to build his file for rating/ranking purposes. But you need to be on a team where your teammates are helping to bring eyes out to see the games.
Most people who go to these events are shocked to learn that there is a venue with this much scouting available. The folks back home will never believe you, if they haven't been themselves. That's nothing, wait until you go to the October tourney in Jupiter some day!