Mike's Questions:
1. What conditions are too much for an average day paddler?
2. Is the average person able to brace his way out of the need to roll?
3. What percentage of people has a roll dependable enough to get them out of real trouble in high seas?

Thank you,
Mike GoodmanJonathan's Answer:
Mike:
Mike, I'll take your last question first. This is nothing but an educated guess stemming from long experience, but I would be astonished if more than one out of 20 of the paddlers you see on the ocean has a really strong roll that could be depended on in high winds and seas. In fact, I wouldn't be at all surprised if the figure was less than one in 50.
Far, far too many sea kayakers either have no preparation at all for a possible capsize, or they simply wedge a paddle float under their deck bungees and imagine they'll figure it out if they ever need the thing. Even those who go to the trouble of learning to roll often take their lessons in a sheltered bay, accomplish two or three successful recoveries, then never practice again. It's a tribute to the intrinsic seakeeping qualities and stability of modern sea kayaks that more people don't capsize in even moderately poor conditions.
To become accomplished at rolling takes three steps: first, you learn to roll an empty boat in a sheltered bay; then you learn to roll a loaded boat in the same place; finally, you practice with a loaded boat in an enclosed, but wind-and wave-swept area. You should also learn to roll up from either side, andperhaps the most difficultyou learn to have the presence of mind NOT to roll immediately if capsized. If possible, take a few seconds to evaluate your position, so you can roll up on the correct side and at the correct moment. For example, it's generally easier to roll up on the windward side, so the force of the wind helps you up instead of trying to knock you back over. Same with waves. Sometimes it helps to first use a sculling brace to bring your head to the surface for a breath and a quick look around before initiating the actual roll.
Now, backwards to question number two, about bracing yourself out of the need to roll in the first place. Yes, it's possible. However, the vast majority of capsizes take the paddler so completely by surprise that there's no time for such a preemptive maneuver. It's just BANG, Hey, what are all these fish doing around my head? And that's when the real expert roller stays cool.
Finally, to your first question, which is the hardest: It's just about impossible to make an objective judgment about conditions. Every "average day paddler" is different, as is every body of water. I could say, for example. "Well, stay out of winds over 20 knots." But there are plenty of circumstances when the wind is lower than that but the waves are dangerously high. Currents? Water temperature? Distance from shore? Large shark fins nearby? You see what I mean.
To tell you the truth, it's not that difficult to judge conditions for yourself. It's also not that hard to become really proficient at rolling. It has nothing to do with strength, and everything to do with technique and practice. And the self-confidence gained by knowing you possess a really solid roll is immense.
Incidentally, Mike, while I stress rolling as the single best primary get-out-of-trouble technique, I also firmly believe every paddler should practice paddle float recoveries just as religiously. The paddle float can be used successfully in extremely rough conditions with proper technique (I discuss it in Complete Sea Kayak Touring). In fact, I'll go out on a limb and say that if you restricted your paddling to warm water, you could be quite well protected with a paddle float and a good grounding in its use. Don't neglect the paddle float roll as an alternative, either. Remember, though, that even in the best of circumstances you are in the water for a much longer time than if you stay in the cockpit and roll back up, and you'll have more pumping out to do.
Many novice paddlers view the possibility of a capsize with dreada totally unnecessary attitude, as long as you are trained to handle the event. Many times capsizing is a great way to just cool off, or to have a look around if you've a mask.
Get out there and practice those recovery techniques. Have fun.
Jonathan