A number of years ago, there was a crash in MN on the St. Croix River just south of Hudson. I don't have the specific details, but the basics of the story was that a large cabin cruiser was leaving the stillwater or Hudson area late at night and was heading south towards Kinni and Prescott. The captain of the vessel claimed that he had not been drinking, but rather that he had turned on the auto pilot and had gone below to use the head. If his story was true, the autopilot failed and took a heading toward the easterly bank of the St. Croix.
In the morning when the call was placed to recover the boat, the authorities found the large vessel some 35' up the rocky embankment. They estimated that he must have been going 30-35 mph when he hit the shoreline.