| 0 - Land |
| 10 - Singlebeam - depth value collected by a single beam echo-sounder |
| 11 - Multibeam - depth value collected by a multibeam echo-sounder |
| 12 - Seismic - depth value collected by seismic methods |
| 13 - Isolated sounding - depth value that is not part of a regular survey or trackline |
| 14 - ENC Soundings |
| 15 - Lidar |
| 16 - Depth measured by optical light sensor |
| 17 - Combination of direct measurement methods |
| 40 - Predicted based on satellite-derived gravity data - depth value is an interpolated value guided by satellite-derived gravity data |
| 41 - Interpolated based on a computer algorithm - depth value is an interpolated value based on a computer algorithm |
| 42 - Digital bathymetric contours from charts - depth value taken from a bathymetric contour data set |
| 43 - Digital bathymetric contours from ENCs - depth value taken from bathymetric contours from an Electronic Navigation Chart (ENC) |
| 44 - Bathymetric sounding - depth value at this location is constrained by bathymetric sounding(s) within a gridded data set where interpolation between sounding points is guided by satellite-derived gravity data |
| 45 - Predicted based on helicopter/flight-derived gravity data |
| 46 - Depth estimated by calculating the draft of a grounded iceberg using satellite-derived freeboard measurement. |
| 70 - Pre-generated grid - depth value is taken from a pre-generated grid that is based on mixed source data types, e.g. single beam, multibeam, interpolation etc. |
| 71 - Unknown source - depth value from an unknown source |
| 72 - Steering points - depth value used to constrain the grid in areas of poor data coverage |