Key:depth

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.

Seamarks

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)

depth:source_quality=*

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)

depth:accuracy=*

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)

depth:exposition=*

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)

depth:technique=*

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