From the Fly to the Sepik River - Getting There / H. Motoring Up the Fly Roger Catchlove, John Clancy and Chris Stevenson Jan 1997

On our way now up the fly river in a boat from Kiunga to Hupen. The guy behind me is Samual Kapuknai who spoke reasonably  good English and arranged (at great expense) to take up 5 hours upstream to Hupen. The river flows quite quickly downstream probably about 5 knots.