Operator of jet ski #1 stated they were going up the Illinois River on the Jersey County side.  He hit an unseen wake that come from the other side of the river. (Calhoun Side).  They jumped the wake. When the jet ski came down, she felt a sharp pain in her back from hitting the seat and exclaimed oh my back.  The jet ski overturned, and the operator and passenger fell off. victim's back was hurt and they couldn't get her back on the jet ski.
Grafton                       