Vessel 1 (''91 Sea Ray) was adrift when impacted on its rear port corner by Vessel 2 (''12 Yamaha PWC).  Operator of Vessel 2 (''12 Yamaha PWC) stated he was coming around on his own wake to jump it when he saw Vessel 1 (''91 Sea Ray) in his immediate path.  Vessel 2 (''12 Yamaha PWC) operator stated he squeezed the throttle control believing it was like a motorcycle and expected the PWC to slow down when it instead accelerated into and impacted Vessel 1 (''91 Sea Ray).
     One of the occupants of Vessel 1 (''91 Sea Ray) who was lying on the back bench seat of the vessel was ejected into the vessel whe was on impacting the hard plastic cup holder.
Boulder City