RedactedNarrative: Unit 1 was pulling a tube with a juvenile and her mother.  Unit 1 had stopped and the tube was parallel to Unit 1.  The juvenile was on the tube and the mother was in the water.  Unit 2 traveled between Unit 1 and the tube that was still attached to the vessel.  Unit 2 struck the ski rope pulling the tube and throwing the juvenile into the water.  Victim on Unit 1 was injured while trying to pull the tube in when Unit 2 struck the rope and pulled him forward in Unit 1.  Unit 2 continued forward until rope shut down the motor.