Or...
contact the closest contest organizer you might want to go to and offer volunteer, they almost always need launch crew. Verify it will be ok to stage your glider and launch after the contest launch, you can then fly the a task that has been assigned for the day. Treat the scorer right and he might even score it for you so you can see how you would have done.

I did this two years ago, I flew a tow plane for the launch and then, on the better soaring days, launched in my own glider after the contest launch was done.

Brian