RedactedNarrative: The vessel was headed downstream on the Tennessee River past the HWY 11 bridge in Loudon, TN. Upon reaching the adjacent railroad bridge, the vessel struck the underwater rocks in the middle of the river.  The vessel lost power and began to take on water.  Loudon Fire was able to respond and guide the vessel to the boat ramp at Malibu Boats.  Upon my arrival, the owners of the vessel had already contacted Towboat US for recovery.  There was three persons on board as well as two dogs.  Priority ambulance was on scene checking on the operator.  He was complaining of a sore neck and back, but he refused treatment.