This was the first of our State8 hikes and we completed it with a 5 person team. We opted to Drive the 2 km from the Camp site to start of the Stair case Spur Track, but you can walk this part too.
I took 6L water and gatorade, but only drank 4.5L
There is an Intention Book to fill out at the base, however this is not checked regularly
It is roughly 1.5 hours to the Bivouac Hut. I found this first part very challenging due to the steep nature of the track. Hiking poles definitely helped on the way up and down here. This section was largely rainforest
From Bivouac Hut to the Summit is another 1.5 hours, but over less challenging terrain. The trees thin out as you ascend and you can see the summit for about 30 mins before you reach it.
(The outer route up is via the Eskdale Spur, which is slightly longer, but apparently less difficult)