RedactedNarrative: Operator had been cruising from Block Island to Hyannis when he collided with a submerged object.  The vessel went down very fast.   The 4 passengers were retrieved by a good Samaritan.  According to a nautical chart it indicates that there were obstructions and rocks awash and or visible at low tide.  No injuries.  Vessel total loss.  MEP was unable to obtain dob of operator.