MLG HAS HDG DEV DUE TO USING VOR RATHER THAN NDB AS NAVAID.

Narrative

WE WERE NAVING ALONG UB-646 FROM CUN TO TPA. UPON CHKING IN THE ZMA WE WERE ADVISED THAT WE SHOULD TURN R 40 DEGS AS WE WERE 16 NM N OF COURSE AND IN AN ACTIVE WARNING AREA. OUR TRIP HAD ORIGINATED FROM MEM AND THE FIRST LEG WAS MEM-CUN. THE CAPT AND I HAD NEVER DONE THAT LEG BEFORE AND WERE NOT AT ALL PLEASED WITH THE LACK OF DEFINITIVE NAV ALONG A-626 FROM GNI TO CUN (A 495 NM LEG). OUR DC-9 WAS EQUIPPED WITH VOR AND NDB ONLY WHICH IS NOT VERY FUNCTIONAL OVER 200 NM. WANTED TO DEPEND ON VOR DUE TO NOT TRUSTING NDB'S. CONTRIBUTION FACTORS: WHEN WE PROCEEDED CUN-TPA (MY LEG) I USED EYW TO NAV UB-646. I HAD FLOWN THE CUN-TPA LEG TWICE BEFORE AND TO MY KNOWLEDGE USED EYW BOTH TIMES. I HAD NEVER NOTICED THAT FIS IS THE NAV FACILITY WHICH MAKES UP THE EASTERN END OF UB-646; NOT EYW. UPON CLOSER EXAMINATION IT WAS CLR THAT THE AIRWAY ENDED AT FIS; NOT EYW. THE CHART IS SOMEWHAT CONFUSING. AN ADDITIONAL FACTOR WAS THE CAPT'S FAILURE TO CONTACT ZMA 10 MINS PRIOR TO REACHING CANOA AS DEPICTED ON THE CHART (IT WAS HIS LEG TO WORK THE RADIOS) AND MY FAILURE TO BACK HIM UP IN THAT REQUIREMENT. ZMA WOULD UNDOUBTEDLY HAVE CORRECTED US PRIOR TO CANOA HAD THIS BEEN DONE. HAVANA CTR WAS NO HELP EITHER AS WE WERE IN RADAR CONTACT WITH THEM AND HAD HAD NO WORD FROM THEM THAT WE WERE OFF COURSE. AFTER ZMA SET US STRAIGHT WE HEARD THEM CORRECT AT LEAST 3 ADDITIONAL ACFT WHO HAD WANDERED INTO THE WARNING AREA. IT WOULD BE INTERESTING TO KNOW IF THEY HAD MISINTERPRETED THE MAP AS WE HAD OR IF THEY SIMPLY WERE POOR NAVIGATORS.