RedactedNarrative: Officer reported that he observed subject operating the 1989 supra exceeding the regulated idle speed restrictions, in addition to the boat possibly being overloaded due to virtually no freeboard.  
  
  Officer motioned to the boat operator to slow down and in doing so the overloaded boat came to abrupt stop, causing the overloaded boat to take on water over the bow.  The boat operator then attempted to accelerate which forced more water into the boat, throwing one occupant overboard, and completely swamping the boat.  The boat then capsized and sank.  All occupants fell out of the boat and were submersed in the water.