RedactedNarrative: Operator stated he was headed up river approximately 28-30 miles per hour when the boat struck an unknown object and ejected him from the vessel.  He stated he tried to swim back to the vessel while it was going in circles, but it was too dangerous.  He stated he swam to bank, watched the boat sink and called for help.  Officer stated the operator had a I phone 12 that was water resistant.  Operator stated a friend came in a boat, picked him up and they searched for the vessel.  Officers was made aware of the incident after the fact several hours later.  Operator stated he was not wearing a life jacket or a engine kill switch.  Vessel was located approximately 10 miles down river the next day.  Vessel had aluminum damage along the starboard side.  Motor had extensive damage to the block, cowling and transom bracket.  Insurance totaled the vessel for $20,000.  Officers observed the capacity plate was rated for a 50 horse power motor and the vessel had a 90 horse power motor on it.  The motor horse power of the vessel is still under investigation with the boat manufacture.  No injuries was reported.