RedactedNarrative: Operator stated that he left Milwaukee Harbor at 2055 and was travelling south to Racine Harbor, at approximately 20-25 MPH, in approximately 15 feet of water. Near the old pier at Grant Park, Operator stated that he struck something submerged in the water and lost engine power. He turned on the bilge pump to drain water from the boat. At 2137 he called 911, stating he was taking on water and lost power. We began our response at approximately 2145 and arrived on scene at approximately 2215. We then towed the motorboat to Bender Park.