RedactedNarrative: Operator and passenger of boat A left dock side bar and grill in the City of Oshkosh heading s/e across Lake Winnebago towards Fond du Lac.  Boat A was following a bigger boat due to the choppy water conditions.  A wave hit the front of boat A causing it to become partially submerged when a second wave hit the front of boat A causing it to become completely flooded.  The bigger boat in front of boat A picked up the operator and passenger and both passenger and operator of boat A said they were uninjured.