i Would say something in the wider family like a Radar Senate, Union or Katana even in probably a 67 given he is going to grow.
The other thing is to slow the boat way down. He should be going no faster than 24 mph to start maybe even 22. That will get him to get around more buoys. 28 or 29 is way to fast to start out. Having enough support to get around buoys without sinking is important.