| NOS/NIMA | IHO/Foreign NIMA Charts | |
|---|---|---|
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Low water line One or two lighter blue tints may be used instead of the "ribbons" of tint at 10 or 20 m |
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Approximate depth contours |
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| Note: The extent of the blue tint varies with the scale and purpose of the chart or its sources. On some charts, contours and figures are printed in blue. | ||