(This January 2011 post was updated and slightly revised in November 2020.)
Cold season kayaking in Northern California is easy, compared to many other parts of the country. Midwestern paddlers have been known to hook their kayaks up to sled dog teams and mush across the frozen tundra. But make no mistake, cold can be a killer anywhere.
Several years ago, I attended a meetup with three Sacramento area kayak groups to discuss safety tips for cold season paddling and watch the following video. Most surprising point? Forget hypothermia – cold shock (hyperventilating) and cold incapacitation (nerve/muscle failure) pose the greatest dangers in the first few minutes after your boat tips over. It may take up to an hour for hypothermia to set in.
Key safety points for cold weather paddling are (1) always wear a PFD, (2) dress for immersion, and (3) paddle with people who know how to rescue and treat a victim in cold water, and be prepared to return that favor yourself. (Practice safe distancing but stay within reach.)
On the second point, consider cold-water clothing. Dry suits are best, a logical first choice, but they’re also expensive. Plus you'll need insulating layers underneath, and the latex neck and wrist gaskets must fit tightly and be maintained to remain watertight. Wet suits are a less expensive alternative, under the right conditions. I've had some past success with a full-length "Farmer John" worn with a windproof splash top. My own preference is a "semi-dry suit" with neoprene gaskets and lighter, Gortex fabric for comfort. These suits may run half the price of traditional drysuits, but they also allow some water inside.
Personal tolerance to cold and wet conditions may dictate your choice. If you've never worn a dry suit before, consider renting before you buy, since returns generally aren't accepted. Check with your local kayak shops or Google for dry suit rentals.
There are other clothing alternatives. NRS, Immersion Research, Kokatat and other outfitters carry cold weather tops and bottoms that retain warmth and repel water. But they usually aren't waterproof. Such cold-weather attire might be okay for flatwater paddling in familiar surroundings under fairly ideal conditions -- but there's no such thing as zero risk. Here's more tips for clothing from a Northeastern outfitter.
In any case, don't rely solely on a color-coordinated, expensive wardrobe to save you in a cold-water emergency. This is very serious business, as a sea kayaking guide attests. And remember there's no shame in drydocking yourself if you feel uneasy with a cold-water paddle. Just curl up by a crackling fire with a good book -- Sea Kayaker's Deep Trouble. It may well reinforce your decision to stay high and dry.