RedactedNarrative: Driver left Clarksville riverside boat ramp at approximately 11:30pm. He traveled up river to Cheatham Dam approximately 15 miles to fish. At 3:15am he left Cheatham Dam and proceeded back down river towards Clarksville.  It was night and in extremely Foggy conditions. Visibility was less than 30 feet. Driver stated he was navigating by a GPS app on his phone and he stated he was at an "high idle" speed and below plan.  However the placement of the damaged vessel and skeg marks on the gravel bank indicated he was on plan and traveling add least 30 mph at the time of the crash. The driver was able to move the vessel from its original resting place and spin the bow back towards the water.  He was unable to move it any further.  The vessel was able to be pulled off the bank by patrol boat and driven back to ramp.