RedactedNarrative: V1 & V2 were traveling up & down the river going around in circles with each other, jumping wakes & splashing each other.  V1 was traveling ahead of V2 while going back upstream toward a sandbar when she looked left & didn't see anything.  She then turned left & only remembers being thrown through the air. V2 states that they were going to cross behind V1 & then come up on the port side when V1 slowed down in front of them, turned left & V2 struck V1 & drove over top of V1.  All subjects were wearing life jackets & alcohol was not involved.