The River Darent rises near Westerham and flows roughly 30 kilometres northward through the villages of Brasted, Sundridge, Chipstead, Otford, Shoreham, Eynsford, Lullingstone, Farningham, Sutton-at-Hone, and Horton Kirby before reaching Dartford and joining the Thames. Beyond Otford, the river transitions into a groundwater-fed chalk stream, creating a diverse habitat for wildlife and vegetation. The final stretch, known as Dartford Creek, meanders between the Cray and Dartford Marshes and marks the boundary between Greater London and Kent. Few boats now use this section of the river.

The Crayford Creek (River Cray) enters the Darent from the right approximately two kilometres upstream from the Thames confluence. Paddlers continuing toward the Thames will pass under the A206 road bridge. The West Kent Main Sewer crosses beneath the Darent in this lower section, and a combined sewer overflow outlet is present nearby. During periods of high rainfall, excess wastewater can discharge into the river at this point, producing a noticeable odour and raising water quality concerns. Paddlers should be aware of this when planning trips through the lower creek.

The tidal Thames confluence means the lower Darent and Dartford Creek are subject to tidal influence. Timing a trip to coincide with the tide is an important planning consideration for this section. The surrounding Dartford and Crayford Marshes are low-lying, wildlife-rich floodplains. Harbour seals have been observed in the broader Thames estuary area near the Darent's mouth.