RedactedNarrative: VESSEL 1 WAS TRAVELLING UP THE SONGO RIVER AT A HIGH RATE OF SPEED. THE WAKE THAT CAME FROM VESSEL 1 CAUSED VESSEL 2 TO BE PUSHED UP ONTO THE BOARDING STEP OF THE DOCK IT WAS ATTACHED TO. ONE OF THE LATER WAVES CAUSED BY THE WAKE OF VESSEL 1 CAUSED VESSEL 2 TO BE PUSHED UNDER THE DOCK AND THEN LIFT IT WHILE UNDER IT.