Question 466Navigation General

The correct answer is A) mean lower low water. The datum used for soundings on charts of the East Coast of the United States is mean lower low water (MLLW). This is the standard vertical datum used for nautical charts in the United States, as it represents the average of the lower of the two daily low tides. This ensures that the charted depths are conservative and that vessels will have sufficient clearance over the seafloor at all times. The other options, mean low water (MLW), mean low water springs (MLWS), and half tide level, are not the standard vertical datum used for US East Coast nautical charts.