Chart Navigation & Plotting · Fixes — Line of Soundings
A line of soundings (a series of echo-sounder depths logged as you run) can be used to:
- ADetermine the compass deviation
- BMeasure the height of tide directly
- CCheck or estimate position by matching the run of measured depths to the charted soundings along the track✓ Correct
- DReplace the need for any chart
Explanation
By recording a series of echo-sounder depths (corrected for the height of tide) at known intervals and comparing the pattern against the charted soundings, the navigator can confirm or estimate position — valuable in reduced visibility or as an independent check on an electronic fix.
Authority: Bowditch (Pub. No. 9), Soundings
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