| Q140003 | When tide corrections are applied, some depths are negative, why is this ? |
| When tide corrections are applied, the sounding values are referenced to a local datum. This means that all sounding values are now (orthometric) heights instead of depths. In fact, you are measuring the elevation of the river bed instead of the depth itself. ... | |
| Tags: Tides, Tide Correction, Orthometric Heights, Elevation, Vertical Datum |
