PILOT OVERFLEW WATER LANDING AREA AT REMOTE LOCATION NOTING THAT HIGH GUSTING WINDS WERE SUBSIDING AND THE LANDING AREA WAS NOW SUITABLE FOR OPERATIONS. AFTER LANDING AND LOADING ONE PAX AND 225 LBS OF CARGO, HE ATTEMPTED WATER TAKEOFF. ON INITIAL LIFT OFF, GUSTS FORCED AIRCRAFT BACK TO WATER, HOWEVER THE PILOT ELECTED TO CONTINUE THE TAKEOFF RUN. BECOMING AIRBORNE A SECOND TIME, THE PILOT LOST CONTROL AT 30 FT ALTITUDE AND CARTWHEELED INTO THE WATER.