Chart Navigation & Plotting · Tides
Charted depth at a buoy is 11 feet; the predicted height of tide is 3.5 feet. Your vessel draws 9 feet. Your underkeel clearance is:
- A2.0 feet
- B5.5 feet✓ Correct
- C3.5 feet
- D14.5 feet
Explanation
Actual depth = charted depth + height of tide = 11 + 3.5 = 14.5 ft. Underkeel clearance = actual depth − draft = 14.5 − 9 = 5.5 ft.
Authority: NOAA Tide Tables; U.S. Chart No. 1
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