LGT HAS NMAC WITH SECOND LGT ON CLBOUT.

Narrative

IMMEDIATELY AFTER CONTACTING DEP CTL AT LAX I WAS GIVEN TFC AT 12 O'CLOCK (LGT ON THE LOOP DEP). WHEN I CALLED HIM IN SIGHT I WAS CLRED VISUAL SEPARATION TO 13000 FT. AFTER THIS I WAS THEN GIVEN A VECTOR OF 160 DEGS FROM MY CURRENT HDG OF 210 DEGS. AS THE FO WAS FLYING THE ACFT AND WE WERE NOW IN A L BANK TO THE NEW HDG; I LOST SIGHT OF THE TFC WHICH HAD NOW STARTED ITS L TURN BACK TO THE LAX VOR. WE DID NOT REGAIN VISUAL ON THE ACFT UNTIL THE FO WAS ROLLING THE WINGS LEVEL AT THE CONCLUSION OF THE TURN. AT THIS TIME THE ACFT WAS AT OUR 10 O'CLOCK POS AND ABOUT 500 FT BELOW US MOVING FROM R TO L. A R TURN WAS INITIATED TO GIVE A LITTLE MORE SPACE AND I ADVISED DEP CTL OF THIS. AFTER THE LGT WAS CLR OF US; I ASKED DEP HOW CLOSE THE ACFT HAD COME TO US. AFTER HE SAID THAT THE 2 TARGETS HAD MERGED ON HIS RADAR HE PROCEEDED TO READ ME THE RIOT ACT OVER THE RADIO. HAD I NOT BEEN TURNED WHEN I WAS; I WOULD PROBABLY NOT HAVE LOST CONTACT WITH THE TFC AND PUT IN THAT POS. ADD TO THIS THE FACT THAT DEPTH PERCEPTION OVER A DARK OCEAN AT NIGHT IS VIRTUALLY NIL AND THIS COULD HAVE TURNED INTO SOMETHING NASTY.