| Removes silt |
| Coats with flour |
| Channel changers? |
| Deepens a channel |
| Scrapes (riverbed) |
| Scrapes the bottom |
| Searches the river |
| Deepens, as a canal |
| Giant silt removers |
| Earth-moving machines |
| Scrapes (river bottom) |
| Scoops up river sediment |
| Land-reclamation machines |