RedactedNarrative: Vessel #1, was cruising at 10MPH, Southbound on Griggs Reservoir approximately one mile South of the Hayden Run Bridge along the West side of the reservoir.  The operator of vessel #1, stated that he traveled between an orange and  white buoy at the end (North) of the rowing regatta race course.  The operator of vessel #1, stated that all of a sudden his vessel sustained a collision with a metal cable submerged underwater that was connected to the floating race course and got wrapped around his propeller.  The force of the propeller drove the cable tight against the lower drive unit.  Note vessel 1, was inspected by reporting Officer after the vessel was removed from the water and trailered to the Marine Park substation the day after the actual collision.  Reporting Officer was not notified or present at the actual collision scene.