A dozen people were rescued Wednesday, after their boat hit a man-made barrier at the Mississippi River lock and dam just north of La Crosse.
Authorities said the boat was going downstream when it hit a wing dam which moves water to a navigation channel.
The motor broke down after the propeller was torn.
The teen and adult boaters threw anchors down, but the fast currents made them useless.
Five people escaped by climbing a ladder on the Dresbach lock and dam.
The other seven stayed in their boat until rescuers from both Wisconsin and Minnesota arrived. All had life jackets.
Fire Chief Bernie Buehler of La Crescent, Minn., said nobody panicked and everyone was safe and sound.
The Mississippi was not flooded at that spot but authorities throughout Wisconsin have warned boaters to stay off raging and flooded waters.