Chart Navigation & Plotting · Tides — Vertical Clearance
A bridge's charted vertical clearance is 60 feet (referenced to MHW). The tide is 4 feet below MHW. The available clearance is:
- A4 feet
- B56 feet
- C60 feet
- D64 feet✓ Correct
Explanation
Vertical clearances are referenced to mean high water. With the tide 4 ft below MHW, available clearance = 60 + 4 = 64 feet (clearance is reduced when the tide is above MHW).
Authority: Bowditch (Pub. No. 9); Chart No. 1
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