NMAC BETWEEN ACR-SMT AND UNK-SMT.

Narrative

FLT WAS OPERATING ON AN IFR FLT PLAN; WORKING ZMA ON FREQ 133.15. WE HAD BEEN CRUISING AT 7000' AND HAD REQUESTED AND RECEIVED CLRNC TO 8000'. AS WE WERE PASSING 7400' I SUDDENLY CAUGHT SIGHT OF AN SMT Y TWIN ENG AIRPLANE AT OUR 3 O'CLOCK POS; HDG DIRECTLY TOWARD US ALTHOUGH SLIGHTLY ABOVE US. FROM THE ANGLE OF THE SIGHTING; IT WAS APPARENT THAT HE WOULD MISS US. THE AIRPLANE WAS VISIBLE FOR APPROX 3 SECS BEFORE IT PASSED SLIGHTLY ABOVE AND BEHIND US. I IMMEDIATELY NOTIFIED ZMA THAT WE HAD JUST EXPERIENCED A NEAR MISS. THE CTLR VERIFIED IT AND SAID THAT THEY JUST RECEIVED HIS MODE C WHICH SHOWED HIM AT 7700'. HE FURTHER STATED THAT HE THOUGHT IT MAY BE AN ACFT WHICH HAD REQUESTED VFR FLT FOLLOWING BUT HAD NOT BEEN PROVIDED THAT SVC DUE TO HVY IFR WORKLOAD. JUST THEN THE SMT Y RPTED TO CENTER THAT HE WAS THE ACFT AND THAT HE HAD HAD THE SMT X IN SIGHT. THE CTLR THEN ASSIGNED HIM A CODE (TRANSPONDER) AND A COM FREQ. THE CTLR ASKED ME IF I WANTED TO TAKE THE INCIDENT FURTHER. I DECLINED THE OFFER BUT STATED THAT I WOULD LIKE FOR THE PLT OF THE SMT Y TO RECITE TO ME THE VFR CLOUD SEP CRITERIA. HE HAD APPEARED OUT OF A SIZEABLE AREA OF FAIR WX TYPE BILLOWING CUMULUS FORMATIONS. I STATED THAT I HAD DOUBTS AS TO WHETHER THE SMT Y WAS ADHERING TO REQUIRED CLOUD SEP CRITERIA. WE HAD BEEN IN AND OUT OF CLOUDS UNDER OUR IFR CLRNC FOR SOME TIME. WE WERE OPERATING WITH 2 OPS ANTI COLLISION LIGHTS; STROBE LIGHTS ON WING TIPS AND TAIL AND NAV LIGHTS ON. I DO NOT BELIEVE THAT OUR PAX SAW THE ACFT NOR HAVE ANY IDEA OF THE INCIDENT.