CLB THROUGH OCCUPIED ALT CREATES AN NMAC IN OVERWATER OP NIGHT OP.

Narrative

APPROX AM10Z; JAN/WED/93; WE ENTERED KINGSTON CTR AIRSPACE (128.1). WE REQUESTED TO LEAVE FL330 FOR FL370. THE KINGSTON CTLR REQUESTED WE CALL WHEN WE PASSED ACR Y (FLT NUMBER UNKNOWN). WE PASSED ACR Y WHO WAS AT FL310. THE CTLR ASKED ACR Y IF THEY HAD PASSED US AND ACR Y REPLIED 'AFFIRMATIVE WE HAVE PASSED ACR X.' WE ALSO INFORMED KINGSTON CTR THAT WE HAD PASSED ACR Y. WE WERE THEN CLRED TO FL370 AND WE DISCUSSED THAT IT WAS STRANGE TO CALL TFC BELOW US AND THEN BE CLRED TO CLB. VISIBILITY WAS ABOUT 4-5 MI AND IT WAS TOTALLY DARK. APPROX 15-20 SECONDS BEFORE THE NEAR MISS WE OBSERVED THE RED AND GREEN WING LIGHTS; SEVERAL COMMENTS AND QUESTIONS ABOUT ALT WERE MADE BTWN THE FO AND I. I DISCONNECTED THE AUTOPLT AND MADE A 45 DEG BANK TO THE L; MISSING ACR Z BY APPROX 100-300 FT AT FL350. WE BELIEVE THE AIRPLANE WAS AN MLG. I INFORMED KINGSTON CTR OF THE NEAR MISS AND ACR Y DID THE SAME. KINGSTON CTR ASKED ACR Y IF HE WAS SQUAWKING ABCD AND ACR Y REPLIED HE WAS 'NOT SQUAWKING.' ACR Y WAS THEN TURNED OVER TO HAVANA CTR (123.7). WE HAD NO TCASII INDICATION WHICH ADDED TO OUR DELAY IN THE EVASIVE MANEUVER.