USCG Exam PracticeApplying tide corrections to charted depth
A bridge has a charted vertical clearance of 20 feet referenced to Mean High Water. The tide is currently 1.5 feet above MHW. What is the actual vertical clearance under the bridge?
- A. 21.5 feet
- B. 20.0 feet
- ✓ 18.5 feetCorrect
- D. 22.0 feet
Why C is correct
Bridge heights are referenced to MHW. When the tide rises above MHW, vertical clearance decreases by that amount. 20 - 1.5 = 18.5 feet. (Bowditch Ch. 9 §904)
Cited:Bowditch Ch. 9 §904