RedactedNarrative: Vessel 1 was heading northeast up the shoreline on the Columbia County side of Lake Wisconsin traveling approximately 45 MPH. Vessel 2 was heading northeast in the middle of Lake Wisconsin traveling approximately 25 MPH following another boat. Vessel 1 turned northwest heading towards a residence.  Vessel 1 turned towards the north to go around another boat and turned back towards the northwest again heading to the residence.  A short time later, vessel 2 struck vessel 1.  Both operator's indicated they did not see each other until the last moment prior to incident.