| 0 - Land |
| 10 - Singlebeam |
| 11 - Multibeam |
| 12 - Seismic |
| 13 - Isolated Sounding |
| 14 - ENC Sounding |
| 15 - Lidar |
| 40 - Predicted based on satellite-derived gravity data |
| 41 - Interpolated based on a computer algorithm |
| 42 - Digital bathymetric contours from charts |
| 44 - Bathymetric sounding - grid |
| 45 - Predicted helicopter/flight |
| 70 - Pre-generated grid |
| 71 - Unknown source |
| 72 - Steering points |