The heights of bridges and overhead obstructions on US nautical charts are referenced to which datum?

A. Mean Lower Low Water (MLLW)
B. Mean Sea Level (MSL)
✓ Mean High Water (MHW)Correct
D. Mean Low Water (MLW)

Why C is correct

Bridge and light heights are referenced to Mean High Water (MHW), not MLLW. As the tide rises toward MHW, the vertical clearance beneath a bridge decreases.

Cited:Bowditch Ch. 9 §904

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The heights of bridges and overhead obstructions on US nautical cha… — USCG Exam Practice · CaptainsGround