RedactedNarrative: While attempting to load the boat onto the trailer, the current started taking the boat downstream to the west side of the boat launch. The aft of the boat was about to strike the pier.  In an effort to correct the boat and prevent contact, the Operator put the boat into the forward gear. When the boat entered the forward gear, the Operator's hand slipped off of the throttle lever. The Operator reached for the throttle lever and failed to get a hold of the throttle lever before the starboard side of the boat made contact with the concrete retaining wall on the east side of the launch. After boat made contact with the wall, the Operator was able to reach the throttle lever and shut the boat down.