The Kolob Pack is a great 37-liter pack for canyoneering in wet canyons. The Kolob is our most versatile pack, and the most popular.
Thirty-seven Liters is a good size for carrying a lot of gear on day trips, and frugal individuals can do an overnight with it. Carefully shaped for optimum performance in canyons, the Kolob works well with Canyon Dry Kegs, though I tend to use drybags exclusively these days.