Chart Navigation & Plotting · Tides — Clearance Under Keel
Charted depth is 18 ft, the height of tide is +3 ft, and the vessel's draft is 16 ft. The under-keel clearance is:
- A2 ft
- B8 ft
- C1 ft
- D5 ft✓ Correct
Explanation
Actual depth = charted depth + height of tide = 18 + 3 = 21 ft. Under-keel clearance = 21 − 16 = 5 ft.
Authority: NOAA Tide Tables; piloting practice
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