Navigation General · Tides
What is the height of tide formula for finding actual depth of water at any time?
- ADepth = Charted depth + Height of tide✓ Correct
- BDepth = Charted depth − Height of tide
- CDepth = Draft + Height of tide
- DDepth = Charted depth × Tidal range
Explanation
Actual depth = Charted depth + Height of tide above datum. Since chart soundings are referenced to MLLW (near the lowest expected water level), adding the current height of tide above that datum gives the actual available depth.
Authority: Bowditch (Pub. 9), Ch. 9
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