RedactedNarrative: Victim and subject untied the boat from the marina dock and started drifting with the current.  The shifter had been left in forward, therefore preventing the motor from cranking.  Victim tied a rope to the stern of the boat and then jumped in the water without a PFD.  He tried swimming back toward the dock while pulling the boat, stern first, behind him.  After approximately two to five minutes, he drowned.  Other subject did not hear him cry out and did try to throw him a PFD to no avail.