V1 left floral city boat ramp heading, (north), onto the floral city lake.  The operator stated that when he was approximately fifty yards from the boat ramp the engine began to run rough.  Operator turned v1 back towards the boat ramp when the engine sputtered.  He added power to keep it running while still in a left hand turn.  The engine again sputtered causing the bow to dive and the vessel to roll to starboard.  When the vessel started rolling he was unable to correct and the vessel rolled over and all occupants jumped off the vessel.  The vessel was completely submerged in approximately ten feet of water.  Operator, and the young female occupant, swam to shore and the  others were having diffuculties swimming.  Operator swam back to assist two.  While trying to keep herself and her son afloat, victim ingested water into her lungs.  victim was taken to shore and transported to citrus memorial hospital and kept overnight for observation.  
No one on the vessel was wearing life jackets and there were no child life jackets on board.
FLORAL CITY