151500 UTC FEB 24 NAVAREA IX 067/24 CENTRAL GULF BAHRAIN CHARTS BA 3736, 3737 AND 3790 BACKFILLING OPERATION AT BAPCO UPSTREAM PIPELINE TRENCH IN PROGRESS FROM POSITION 26-11.18N 050-39.25E TILL POSITION 26-12.04N 050-39.60E (.) MARINERS CAUTIONED