RedactedNarrative: Vessel 1 northbound on St Croix River approaching Stillwater lift bridge.  Lift bridge was lowering and Vessel 1 attempted to make it under the bridge.  Vessel 1 Operator realized vessel was not going to clear bridge and threw boat into full reverse.  Vessel 1 did not stop and struck bottom of bridge.  Top cabin of Vessel 1 was knocked off.  Passenger was injured with laceration to upper left leg.  Bridge operator stated he saw the vessel attempting to make it under bridge and when he realized the vessel was potentially not going to make it he stopped the bridge.  Vessel 1 Operator estimated speeds at impact to be 10-15 miles per hour.  No damage was observed to bridge.