If you will tell me the time that it takes you to make a turn (entrance to exit in seconds) and about how far off the buoys you are, it is not a difficult measurement.
We have done many calculations using the applet that Brian Callahan developed to do exactly that. Some of the findings are: (average g's in the turn)
My 20 rigger - 5.0, My 67 Roadrunner - 6.1, Brian's 67 Roadrunner - 8.5, a 45 OB Tunnel - 2.5.
As you can see there is a very wide spread. I would suspect that the JAE 21 would be in the 4 - 5 range.