Operator1 was in the water beside his pwc (vessel 1).  Vessel 2 accelerated into operator1.  Operator1 lifted his arms in defense.  Vessel 2 glanced off of operator1's arm, straining his rotator cuff, then proceeded over the top of vessel 1, breaking the gas cap off of vessel 1.  Vessel 1  also sustained minor scuffs to the rub rail.  Vessel 2 sustained minor scratches to the bottom of the hull.
Noblesville