From April to November, Nitmiluk Tours hires out single/double canoes for a half-day ($57/91 plus $50 deposit, departing 8am and 12.30pm), including the use of a splash-proof drum for cameras and other gear (it's not fully waterproof), a map and a life jacket.
The half-day hire only allows you to paddle up the first gorge; with the full day you can get up as far as the third gorge depending on your level of fitness − start early. You can also be a little more adventurous and take the canoes out overnight − there are camp sites at the fifth, sixth, eighth and ninth gorges. Bookings are essential as overnight permits are limited and there is a $60 deposit. Don't take this trip lightly though.
The canoe shed is at the boat ramp by the main car park, about 500m beyond the Nitmiluk Centre.