Operator and 4 passengers (3 of which are unknown) were on a fishing trip offshore.  The weather got bad and the sea conditions got very poor so operator was attempting to return to shore.  The motor died for unknown reasons, causing the vessel to go dead in the water and turn broadside to the seas.  A large wave swamped the vessel.  Operator was unable to get motor restarted after it got submerged.  Operator hailed for assistance on VHF radio, deployed the anchor, and the passengers were able to bail the vessel using buckets.  I, Investigator with FWC, arrived on scene and maintained contact with the operator and occupants but was unable to transfer them to my vessel due to dangerous sea conditions.  Tow Boat US arrived on scene and towed the vessel and occupants to shore.  No passengers were injured but the motor was a total loss.
MARCO ISLAND