Operator said he hit a floating object while cruising in the main channel of the Mississippi River heading upstream near Princeton Beach.  He then motored to the beach as his vessel filled with water.  He was able to beach the vessel but it eventually filled with water, overtopping the inboard engine.  I viewed the damage to the vessel while it was on a forklift at the Drystack Marina in LeClaire.  It appeared that the damage  was very severe with secondary stress cracks to the left lower transom, and was likely caused by a solid object such as a submerged  rock wingdam.  There is a wingdam on the Illinois side of the main channel near where the operator reported the collision took place.
Princeton                     