RedactedNarrative: Vessel 1 was traveling North bound in Mobile Bay near Pointe Clear.  Vessel 1 struck a swimmer outside of the Grand Hotel''s Swim Area.  The swimmer heard and observed the vessel.  The swimmer swam down into the water in an attempt to avoid being struck by the vessel.  The swimmer made no attempts to wave or notify the vessel of his presence.  The vessel operator nor passenger observed the swimmer prior to impact.  The lower unit (propeller) on vessel 1 struck the swimmer''s left and right legs.  After impact, the vessel turned around to investigate what the vessel struck.  The operator and passenger of vessel 1 pulled the swimmer into the boat and brought him to shore for medical attention.  The swimmer was transported to Thomas Hospital for medical treatment.  I observed no buoys or signs that designate a swim area or boat exclusion zone.  The Grand Hotel has two beach areas where hotel customers swim and access the water.  The swimmer''s wife was on the beach near these swim areas during the incident.