Colne Brook between Wraysbury Station and Hythe End.
The Colne Brook has a decent flow and the base is mainly gravel. Clear water with few reeds. Either park at south end of footpath at Hythe End and walk north for half a mile or so or walk from Wraysbury station. Map needed!. The river is mainly hidden from the path except at a few places. Every possibility of skinny-dip. Lovely river location with reeds and willows.