RedactedNarrative: Subjects were out scouting duck/goose hunting location on the Wisconsin River as the early teal and goose season open the following morning. Subjects had put in at the portage boat launch at Summit and Carrol St and went downstream. Operator of the boat verbally told Subject they were going about 15-20 miles an hour and were about to give it more throttle to get up on plane when they struck something under the water line and sent both himself and his passenger to the front of the boat. Both subjects stayed in the boat but slammed hard into the front of the boat which had a covered storage area and a large docking light attached to the bow. They were able to free the boat eventually and made it back upstream to the boat launch. 
  
  Subject searched records for the structure and found the city was required to mark the structure per the permit issued to install the sewer plant. No waterway marker permit to place buoys to mark the structure is on file with the WI DNR.