Drysuits are the preferred method of cold water thermal protection for very cold canyons (32°-50°F) - where extended & continuous exposure is expected.

Whitewater kayaking drysuits are the standard to be covered here. Certain types of water ski drysuits are similar to kayaking drysuits, frequently less expensive, and similarily constructed. We have limited experience with Scuba drysuits and have never seen one used on the Colorado Plateau.

Introduction: Drysuits are typically made of a waterproof coated-nylon body with rubber waterproof gaskets that seal about the neck, ankles, and wrists. A waterproof zipper across the front allows entry and exit into the drysuit.

Shopping for a drysuit: We recommend Kokatat, Stohlquist, and Palm for purchasing a new drysuit. You'll want to look into the following features & special options:

Gore-Tex: Expensive but worth it, say the people who use it.
Relief Zipper: Of all the places I've skimped on my canyoneering gear, this is the one I regret the most. Get one, whether you can afford it or not.
Integral booties: We haven't used them nor needed them (thick neoprene socks or SealSkinz waterproof socks have worked fine) but have heard good things from those who have.
Cordura Reinforced Seat and Knees: Absolutely essential. Even with this feature, you'll want to further protect your drysuit from abrasion with some customizations (see below).

What you don't want:
Overskirt: Good for kayaking, bad for canyoneering. Gets in your way, obscures your harness & gear, bad news.

Gasket Care: The best primer on general gasket care (and drysuit care as a whole) is at Kokatat.

Specific issues to Canyoneering -
Putting on your drysuit: To avoid tearing gaskets, some canyoneers lubricate the latex with a small amount of sunscreen. Peope with especially hairy legs may find the ankle gaskets especially difficult to put on.

When using with neoprene socks, the common layering configuration is skin, latex gasket, neoprene sock, drysuit velcro protective cuff.

Be careful not to pinch or touch the latex gasket with any sharp object (watch the long fingernails), especially while the rubber is in tension. Pull slowly and evenly. Don't force it.

Drysuit care in transit: Some canyoneers have torn their gaskets while merely packing their drysuit to the put-in, catching the latex on a zipper or tree branch. You can avoid such accidents by tucking the neck gasket into the suit body, and tucking the ankle & wrist gaskets into the sleeves and then securing the velcro cuffs securely over the openings.

Drysuit care in the canyon: Make sure you buy a drysuit with protective nylon cuffs that secure over the latex. Use them! The space between the cuff and the gasket can also be a handy place to carry spare energy bars or a pocket knife on a wrist strap. Many of us wear cheap nylon river shorts over our suits to provide further abrasion protection for the rear; some have started to wear neoprene braces over their knees and elbows as well.

Jumping: Many canyoneers have expressed concern about plunging into water with a drysuit, for fear of rapid forced air evacuation tearing a neck gasket. Preliminary tests seem to indicate that properly "burping" (pre-evacuating air from your drysuit) will alleviate this problem; we've seen 30' plunges executed in this manner without incident.

Aquasealing your drysuit: It's a good idea to reinforce the high wear areas of your drysuit with Aquaseal, Freesole, or some other flexible adhesive repair goo. Important areas tend to be the rear, hips, shoulders & outer bicep, elbows, and forearms. Once dry, Aquaseal is slippery when wet, so some modfiy their reinforcement coats by sprinkling sugar or sand on the Aquaseal before curing. I haven't found this neccessary, as untreated Aquaseal tends to grip to sandstone just fine for my tastes.

Mixing Aquaseal with Cotol-240 will shorten the curing time from two days to two hour. Highly recommended, especially for your repair kit.

Check out this excellent article on drysuits by Michael Henkin.