SMA HAS NMAC WITH SMT NEAR UNCTLED ARPT.

Narrative

10 MINS PRIOR TO THE INCIDENT I DEPARTED JEKYLL ISLAND; GA (09J); AN UNCTLED FIELD; ON RWY 36 ON A VFR FLT PLAN TO ATLANTA; GA; LNDG PDK. INCLUDED IN THE PLAN WAS A SIGHTSEEING CIRCLE OF JEKYLL ISLAND. THE LCL FBO STATED THAT THE NORMAL PROC FOR SUCH A CIRCLING OF THE ISLAND WAS TO ANNOUNCE SUCH INTENTIONS ON CTAF (123.0); CIRCLE THE ISLAND IN A CLOCKWISE DIRECTION; REMAIN CLR OF POPULATED PORTIONS OF THE ISLAND; AND ANNOUNCE LOCATION OVER 123.0; WHILE LISTENING FOR OTHER ACFT. AFTER DEPARTING; I ANNOUNCED LOCATION AND INTENT AND COMMENCED A CLBING CLOCKWISE CIRCLING OF THE ISLAND. AFTER REACHING THE SOUTHERN TIP; AND STILL IN SIGHT OF THE ARPT; I CONTINUED A CLBING R TURN TO INTERCEPT V 179 DEFINED BY THE 326 DEG RADIAL OF THE BRUNSWICK VOR (SSE 109.8) LOCATED 2 MI SW OF THE ARPT. AT 2500 FT AN SMT CROSSED IN FRONT OF ME IN A NEAR MISS ESTIMATED AT 50 FT ABOVE AND 200 FT AHEAD. THE OTHER ACFT WAS IN A R WING LOW; 20 DEG L CRAB; DSCNT CONFIGN AND CROSSED FROM ABOVE AND BEHIND MY 8 O'CLOCK TO AHEAD AND BELOW MY 2 O'CLOCK POS. THERE IS NO WAY I COULD HAVE SEEN THE OTHER ACFT AS IT WAS DSNDING FROM ABOVE AND BEHIND ME. AS THE OTHER ACFT DID NOT COME INTO VIEW UNTIL 50 FT ABOVE AND 200 FT IN FRONT OF ME; THERE WAS NO TIME FOR EVASIVE ACTION. I WATCHED THE OTHER ACFT FOR SOME TIME AND IT APPEARED TO BE ON A DSCNT TO THE MCKINNON ARPT (SSI) SOME 10 MI TO THE N. MY ONLY SUGGESTION IS THAT ACFT DSNDING OVER AN UNCTLED FIELD SHOULD MONITOR THE CTAF FOR THAT FIELD. THE OTHER ACFT WAS NOT ON 123.0 AND WAS PROBABLY COVERING 122.7; CTAF FOR SSI. WHERE 1 FIELD LIES CLOSE TO ANOTHER AS IN THE CASE OF 09J AND SSI IT MIGHT BE USEFUL IF BOTH HAD THE SAME CTAF. ANOTHER SOLUTION; WOULD BE TO HAVE ACFT ANNOUNCE LOCATION AND/OR LNDG INTENT ON BOTH FREQS.