Coastal Skipper and Yachtmaster Quiz · Tidal calculations
You are choosing where to anchor for the night. With these figures, what is the least depth of water you should anchor in now?
A cross-section of a yacht at anchor over a flat seabed. The sea surface is labelled: now, height of tide 3.8 m. A dashed line lower down is labelled: low water 0.9 m. Draught 1.8 m. Caption: wanted under the keel at low water, 1.0 m. A gold arrow with a question mark runs from the present sea surface down to the seabed.
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5.7 m. Work out how far the tide still has to fall: 3.8 minus 0.9 is 2.9 m. At low water you want your draught plus the clearance, 1.8 plus 1.0, which is 2.8 m. So the depth now must be at least 2.8 plus 2.9: 5.7 m.
