RedactedNarrative: Vessel one was underway, northbound, and struck a submerged object.  The object dislodged the outboard motor and busted the transom.  The dislodged motor struck the portside pontoon.  The pontoon began taking on water.  Operator of vessel one and an unknown boater attempted to tow the damaged vessel back to the boat ramp. They were unable to tow the vessel and tied it off to a fallen tree.