GROSS NAV ERROR RESULTS IN TRACK POS DEV.

Narrative

UNEVENTFUL SCHEDULED FLT OF ACR X FLOWN IAH TO MID (MERIDA; MX) AM53 TO AM54 CST AT FL330; EXCEPT WINDS HIGHER THAN FORECAST; 250/78. DEPARTING MERIDA AT PM30; MERIDA CTL HELD US TO FL260 DUE TO HIGHER TFC AT FL280; FL310; FL350. MERIDA CTL GAVE AN INCORRECT (N SECTOR) CONTACT HOUSTON FREQ 133.65 TO US AND THE 3 HIGHER ACFT FOR ADIZ CHKS IN AT BARROWS. UTILIZED THE FL350 ACFT TO RELAY CHK-IN FOR MARTA AND BARROWS WITH HOUSTON CTR. OVERCORRECTED FOR LOW ALT WINDS AND WAS RPTED 36 MI W OF TRACK BY ZHU; WHEN ON CORRECT 132.4 FREQ. THOUGH NO MEA ON THE GULF RTE PUBLISHED ON CHART; OUR ACR USES FL270 ON A-766 AND FL280 UB 753; WE FOUND OUT LATER -- ALSO WHEN UNABLE TO CONTACT ZHU; THERE IS AN ARINC 130.7 FREQ AVAILABLE. OVERWATER NAV ERROR RPT FILED BY ZHU. SHOULD HAVE USED ONLY MAGNETIC HDGS FROM FLT (FL350) PLAN FOR RETURN LEG OR REDUCED WIND CORRECTION AT ACTUAL CRUISE ALT OF FL260. KNOWING OUR ACR HAD ESTABLISHED MEA'S OF 270/280 FOR RTE AND THAT; AT OUR TIME OF DEP; ONLY 260 WAS AVAILABLE -- I WOULD NOT HAVE DEPARTED UNTIL A HIGHER ALT WAS AVAILABLE. TO CONDUCT FLT AT SUCH A LOW ALT LED TO A COM AND NAV PROBLEM FROM DISTANT VORS TO ESTABLISH CORRECT WIND INFO AND REQUIRED POS RPTS.