QUASOU

1. depth known: the depth from chart datum to the bottom is a known value.
2. depth unknown: the depth from chart datum to the bottom is unknown.
3. doubtful sounding: a depth that may be less than indicated. (adapted from IHO Dictionary, S-32, 5th Edition, 4840)
4. unreliable sounding: a depth that is considered to be an unreliable value.
5. no bottom found at value shown: upon investigation the bottom was not found at this depth. (adapted from IHO Dictionary, S-32, 5th Edition, 4848)
6. least depth known: the shoalest depth over a feature is of known value. (adapted from IHO Dictionary, S-32, 5th Edition, 2705)
7. least depth unknown, safe clearance at depth shown: the least depth over a feature is unknown, but there is considered to be safe clearance at this depth.
8. value reported (not surveyed): depth value obtained from a report, but not fully surveyed.
9. value reported (not confirmed): depth value obtained from a report, which it has not been possible to confirm.
10. maintained depth: the depth at which a channel is kept by human influence, usually by dredging. (IHO Dictionary, S-32, 5th Edition, 3057)
11. not regularly maintained: depths may be altered by human influence, but will not be routinely maintained.