USCG Exam PracticeTides and currents — predictions and corrections
The vertical clearance of a bridge charted on a US chart is referenced to which datum?
- A. Mean Higher High Water (MHHW)
- B. Mean Lower Low Water (MLLW)
- ✓ Mean High Water (MHW)Correct
- D. Mean Sea Level (MSL)
Why C is correct
Bowditch Ch. 9 §904 specifies that heights of features such as bridges and lights are referenced to Mean High Water, which means vertical clearance decreases as the tide rises toward MHW.
Cited:Bowditch Ch. 9 §904