RedactedNarrative: THE OPERATOR OF VESSEL 1 WAS RENTED AND TRAVELING ON LAKE ST CLAIR AND NOTICED A CRACK IN THE STERN/TRANSOM HOLDING THE ENGINE. DURING THE VOYAGE THE ENGINE BROKE OFF THE TRANSOM AND FELL INTO THE LAKE MAKE THE VESSEL INOPERABLE. THE INCIDENT CAUSED THE NEED FOR THE OCCUPANTS TO BE RESCUED AND VESSEL 1 NEEDED TO BE TOWED. NO INJURY, NO ALCOHOL REPORTED.