Protecting Your Camera Gear in the Zion Narrows:
River canyons like the Zion Narrows are rewarding for photography, but they are treacherous for expensive camera gear. When you hike the Narrows in normal conditions, you are typically hiking in knee to waist-deep water and occasionally, there may be one or two short sections of chest-deep water. (The base of Mystery Falls near the Temple of Sinawava is often deep.)
At several river crossings in the Narrows, the current can be quite powerful and it takes a great deal of balance and strength to keep from falling over. And in higher water conditions, hiking is even more difficult. Needless to say, this is a dangerous situation for your exposed camera gear.
When I hike with my big camera, I typically stow it in a small toploader camera bag and use a short run of webbing and a small carabiner to attach it to a high point on the shoulder strap of my backpack. That puts my camera pretty high at chest level, yet keeps it easily accessible for shots.
For balance and support, I use my big, sturdy tripod as a walking stick alongside one of my normal trekking poles. For added safety it is important to also bring a drybag for your camera and other electronics that fits in your backpack (like the Sea to Summit eVac Lightweight Drybag 35L), just in case you need to stow all of your camera gear for a precarious section of river. I also put a small towel inside the drybag to soak up any drops of water that might make their way inside. Be sure to test out your rig before your big hike. See the Hiking Gear page for more suggestions.
If you are looking for an easier solution to getting souvenir photos with your smart phone, simple cases like the ProCase Waterproof Pouch have become very popular for canyon photography. None of these cases are completely foolproof though, so be sure to test your rig out before your big hike.
Camera manufacturers like Olympus and Ricoh make convenient waterproof cameras, but none of these models have very good resolution that make it worth using over your smart phone. Development of high-quality touch/waterproof cameras has sadly stagnated over the past two decades.
Thoughts on Canyoneering Photography:
For other wet canyon hikes like Orderville Canyon, the Left Fork of North Creek (the Subway), and many of the technical canyoneering routes in Zion National Park, you can pretty much count on having to swim several times, so be prepared to constantly set up and stow your camera gear in a drybag or other protective waterproof case.
In consistantly wet sections of canyon, you will also have to battle lens fog, moisture build-up, and fine particles of sand that like to get in the buttons and dials of your camera. That's the risk you take to get great photos in such difficult locations. Be prepared for the possible loss of your gear.

