Used to fish that canyon in my twenties...alot of trekking involved.that area is severe wilderness speyfitter. Good luck on your quest.
I'm well aware of the dangers involved. Just to give you an idea of my preparations:
1) Will not do alone obviously - will have a buddy with me who will be as prepared as I am.
2) At least one Personal Locator Beacon between the two of us
3) Full wetsuits or drysuits with PFD's, & Helmets
4) I will have my brother dropping us off and picking us up
5) Contemplating and when the day comes (I'm not that close YET as I still have more prep work to do and places I want to go/see first, plus
things to buy too, before getting there) either trying to hook up with some Kayakers for safety in numbers and/or hiring a whitewater guide for the first time down.
6) I've got good guides on this section, as well as seen a few good Kayaking videos, as well as there are lots of guys who believe it or not Canoe the canyon at lower water levels.
7) I'm talking ANOTHER pontoon course this coming May (took one a few monthes ago, plus have some experience) as well as I won't go before I have some swiftwater rescue training.