| NOS | NIMA | |
IHO/Foreign NIMA Charts | |
|---|---|---|---|---|
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Limit of dredged area |
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Dredged channel or area with depth of dredging in meters |
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Dredged channel or area with depth and year of the latest control survey |
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Dredged channel or area with maintained depth |
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Depth at chart datum, to which an area has been swept by wire drag. The latest date of sweeping may be shown in parentheses. |
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Unsurveyed or inadequately surveyed area; area with inadequate depth information |
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