USCG Exam PracticePlot true course and distance between two charted points
On a US nautical chart, soundings are referenced to which datum?
- A. Mean High Water (MHW)
- B. Mean Sea Level (MSL)
- C. Mean Low Water (MLW)
- ✓ Mean Lower Low Water (MLLW)Correct
Why D is correct
US charts reference soundings to Mean Lower Low Water (MLLW). The unit of measurement (feet, fathoms, or metres) is stated in the chart title and must be verified before plotting.
Cited:Bowditch Ch. 4 §403