RedactedNarrative: In channel entering Sag Harbor after passed Cedar Point. Large vessel in opposing direction travelling at high rate of speed created large wake. Slowed vessel in anticipation, and did best to avoid wake, although narrow channel and boat traffic. Slowed vessel and crossed wake at approx. 45 degrees. Passenger injured ankle from impact. Called dock master to arrange Police/EMS standby. Arrived at floating dock at waterfront Marina approx. 5pm, and Emergency personnel was waiting and rendered assistance.