RedactedNarrative: UNIT 1 WAS TRAVELING NORTHBOUND ON CASTLE ROCK LAKE JUST SOUTH OF THE BUCKHORN BRIDGE. OPERATOR BELIEVED HE WAS OPERATING ON THE WISCONSIN RIVER CHANNEL SOUTH OF THE RAILROAD TRESTLE. BOAT STRUCK THE CAUSEWAY WHILE TRAVELING AT APPROXIMATELY 20-25MPH CAUSING DAMAGE TO THE BOAT AND GROUNDING IT ON THE ROCK SHORELINE. NO ONE WAS SIGNIFICANTLY INJURED. OPERATOR WAS ARRESTED FOR BOAT OWI 1ST. SEE INCIDENT REPORT FOR FURTHER INFORMATION.