 HISTORY
  ****SOURCE UNKNOWN; APPEARS AS SUBMERGED STRUCTURE PA ON 24TH ED, 10/11/75 , OF CHART 18421  IN POS.48-32-44.2 N  123-00-30.4 W (PRESENT NAD 83 POS.). ENTERED 3/00 MCR
    F00459/00--OPR-N411-NRB: The search area is a steep slope near shore.