HISTORY
  Charted shoal.
  H4711/27--Source for charted shoal of 0.2 fathoms MLLW at 47/57.23N, 122/40.57W.
  H8912/66--Items for Future Presurvey Review,   A charted shoal of 0.2 fathoms MLLW at 47/57.23N, 122/40.57W.
Several rocks, piles, and shoal