Chart Navigation & Plotting · Tides — Depth of Water
A chart shows a charted depth (sounding) of 11 feet at a spot. The height of tide at your time of transit is +4 feet. What is the actual depth of water?
- A4 feet
- B7 feet
- C11 feet
- D15 feet✓ Correct
Explanation
Actual depth = charted depth + height of tide = 11 ft + 4 ft = 15 ft. Charted soundings are referenced to the sounding datum (MLLW in the U.S.); the height of tide is added to obtain the real depth.
Authority: Bowditch (Pub. No. 9); Chart No. 1
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