RedactedNarrative: Operator of vessel #1 (Operator) had been drinking earlier in the day.  He took his nephew (Passenger1) and his friend (Victim) out on his boat.  While heading east past the Ambassador Bridge, Operator went to turn around.  As he was turning around, the motor stalled.  He raised the motor to see if there were any obstructions on the prop.  There were none.  He disconnected the battery and fixed the issue.  As they drove past the Riverwalk, they tried to turn and ran into what he described as a “barge”, but was determined to be the pier of the river.  Victim fell off the boat as a result.  Passenger1 threw a lifejacket to Victim, but he was unable to grab it.  Operator jumped into the water, attempting to save Victim.  Fatigued, Operator got back into the boat, donned a lifejacket and reattempted to rescue Victim. They called 911 shortly after.  No one was wearing a lifejacket prior to the accident.  No other injuries were reported.  No citations were written.  MSP had done a PBT on Operator at the time of the accident and his BAC was .10.