 CL 490/53, 11/5/1953; REPORTS A DANGEROUS SUBMERGED OBSTRUCTION IN LAT. 28/58.7 N, LON. 91/28.7 W. (NAD27) THE SHOAL RUNS IN AN EAST-WEST DIRECTION AND APPEARS TO BE ABOUT 250' LONG AND 50' WIDE.  THE DEPTH OF THE GULF IN THIS VICINITY IS 39-40 FT, BUT