  CL1689/77--USPS;  WRECK BY SOUTH CAUSEWAY FIXED BRIDGE IN 30/08/18.00N, 090/08/30.00W (NAD27) HAS A REPORTED CLEARANCE OVER THE WRECK OF 7 FEET BY A CERTIFIED DIVER DURING REMOVAL OF 50' TRAWL.  OBSTRUCTION WAS MARKED WITH A CLOROX GALLON JUG ON 7/15/7