RedactedNarrative: Operator #1 turned from a southbound travel toward Lock and Dam 5a to investigate a possible stranded boater. He didn't find the disabled boater. Operator #1 then proceeded to turn around again and continue southbound about 3/4 of a mile above Lock and Dam 5a. The operator accelerated. When the boat started planing off, at about 30 MPH, the boat impacted a large green channel marker buoy on the Minnesota side of the river. The buoy placed a 24 inch hole in the front of the boat, causing severe damage. The boat was able to maintain flotation. Lock and Dam 5a notified the Sheriff's Office when the boat came into lock. There were no injuries and all aboard were wearing life jackets. Alcohol was not a factor.