RedactedNarrative: Vessel 2 was trolling at approximately 2.5 MPH, heading towards the dam.  The passenger of vessel 2 was relieving himself at the starboard stern of the boat.  He stated he observed vessel 1 coming right at them.  The passenger turned and let his brother, the operator, know this boat was coming.  They both dove into the from floor of the boat, causing abrasions to the passengers face.  Vessel 1 made contact with vessel 2 between the ladder and engine of the vessel 2.  Vessel 1 ramped over vessel 2, causing significant cosmetic damage to vessel 2.  Vessel 1 and 2 was operational after impact.  Vessel 1, according to the operator, was traveling at 24 mph, and didnt see vessel 2 until they hit.  Both vessels had operational navigation lights.  Damage to vessel 1 was unknown.