Imagine Little Susitna boulders with drops twice as tall as Ship Creek and five times as numerous: that’s the Arahura at low water.
There are hiking guidebooks and maps for the hiking and Graham Charles for the boating (http://rivers.org.nz/nz/west-coast/arahura/arahura-gorges), with huts for the camping.
Here’s a video about the packrafting: