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Public-images-osm logo.svg depth
Great Bear Lake (depth information).png
The depth of a feature, in metres. Edit or translate this description.
Group: Properties
Used on these elements
may be used on nodesmay be used on waysmay be used on areasshould not be used on relations
Status: de facto

Depth is a property referring to how deep a feature is according to charted depth, measured in metres. For shallow depths, such as some fords, a decimal value will be needed - e.g. 0.05 for 5 cm. In most cases, the depth of a feature in the ocean is referred to LAT (Lowest Astronomical Tide). For rivers, canals, and inland lakes this might be different. Rivers and canals with water level gauges will have a defined zero value where depths should be referred. For more background information, see Water Depth.


When depth=* is used with Seamarks, you may want to add these additional tags, which correspond to attributes from IHO S-57:

Source Quality (QUASOU)

OSM Value S-57 Index S-57 Long Value
known 1 depth known
unknown 2 depth unknown - You should never use this value, just omit the depth=* tag
doubtful 3 doubtful sounding
unreliable 4 unreliable sounding
no_bottom 5 no bottom found at value shown
least_depth_known 6 least depth known
least_depth_unknown 7 least depth unknown, safe clearance at value shown
not_surveyed 8 value reported (not surveyed)
not_confirmed 9 value reported (not confirmed)
maintained 10 maintained depth
not_maintained 11 not regularly maintained

Accuracy (SOUACC)

This field is a number, in metres, such as 0.6. The error is assumed to be positive and negative. The plus/minus character shall not be encoded.

Exposition (EXPSOU)

OSM Value S-57 Index S-57 Long Value
within_range 1 within the range of depth of the surrounding depth area
shoaler 2 shoaler than the range of depth of the surrounding depth area
deeper 3 deeper than the range of depth of the surrounding depth area

Technique (TECSOU)

OSM Value S-57 Index S-57 Long Value
echo 1 found by echo- sounder
sonar 2 found by side scan sonar
multi-beam 3 found by multi-beam
diver 4 found by diver
lead-line 5 found by lead-line
wire-drag 6 swept by wire-drag
laser 7 found by laser
acoustic 8 swept by vertical acoustic system
electromagnetic 9 found by electromagnetic sensor
photogrammetry 10 photogrammetry
satellite_imagery 11 satellite imagery
levelling 12 found by levelling
sonar 13 swept by side-scan sonar
computer_generated 14 computer generated