Words words... The section is known as "Harrington canyon" section. This avoids confusion.
The lower section, which ends in the Ottawa river, is entirely feasible at 160 on the gauge, even in a playboat (I've done it), but many swam that day. Let's say the run is a bit... stressful. And there is significant current just where you need to take out to portage the falls.
On the other hand at this level, the Harrington canyon section has only one major rapid which ends in a big 'lake', and the rest is just fun.
Is anyone leaving from Ottawa? We can meet at my place at 8:15 (87 Goulburn--convenient location) to sort things out... I will be celebrating a friend's birthday tonight, but my mobile phone # is 613 355 2470.
--C.