This is sort of (semi-)combat roll. Not in the foamy water but just swift current.
I had in the past thought rolling in the current should be no different from rolling in flat water. That is, after the boat “equalize” to the speed of the current. Once the boat is moving with the speed of the current, it ought to be “just like” rolling in flat water? I’ve rolled in slow moving water and felt it was no different from flat water roll…
But I found it quite a bit harder to roll in faster moving water. The primary difficulty I experienced was I had trouble getting setup properly. I couldn’t quite get my hands and body to the surface. I ended up rolling without an “ideal” setup. It was a shaky roll but nonetheless I got up.
I’m just wondering what the experience of other WW rollers are like. And tips for a solid/bomb-proof moving water roll.
upstream/downstream
Makes a difference
Once you develop awareness, you can, actually, choose the side on which you want to set up - paddle on the upstream side requires a bit more effort to set up, and to roll up, paddle on the downstream side is almost effortless.
Oh, most often folks capsize to the upstream side, it is natural to roll over and end up rolling downstream side. Exception is getting flipped close to rocks - choices become very limited 
Difference
Well, in swift water you are obviously distracted by two things: you find yourself upside down with the current yanking on the paddle, and you have to struggle to drag the paddle into a setup position, and also you are moving quickly in the current so if there are any rocks you will be vulnerable to collisions. Sometimes you are immediately dragged over or battered against rocks.
Good tip!
That’s good to remember. Indeed I was on the upstream side (which I didn’t realize) and having a difficult time to get my paddle to the setup position.
Knowing it’ll be a bit easier on the other side will be helpful. I do have a “preferred” side which I automatically go to. But if that fails, I’ll try the other side. It’s my weaker side, but it being easier, it might actually work out just fine.
extra sweeps
I haven’t been doing much whitewater these days - too far to travel from here, and limited whitewater river experience overall anyway, but when I’m not confident I’m in a good position to roll, I typically do a normal sweep back, ready to do another sweep forward, which sets me up to do another sweep back. In my experience in whitewater, I’ve usually been up by the 1st or 2nd sweep, and by the start of the third sweep, I’m very likely to be in good position to roll up if I wasn’t before. Of course a sweep roll can be slipped into a finish with a high or low brace too if I find myself most of the way, but not quite far enough up.
In surf I learned quickly that it’s pretty much mandatory to feel your way with the paddle towards the low resistance side. That leaves my kayak being pulled along by the wave with my body dragging behind it at the surface, ready to right myself when hopefully appropriate. Sounds similar to bringing your paddle to the downstream side when the current is moving faster than your boat. I would think the feeling out process underwater of allowing your paddle and arms to go with the current would be similar anyway. Makes sense that bringing that upstream edge underwater with your paddle on the downstream side would flip you right up.
Offside roll
Develop and practice your offside roll, so when you have difficulty on one side (current, hole, etc.) it’s a fast switch to the other. When you practice your rolls, do so in a variety of positions and don’t commence until you’re upside down a few seconds. Practicing from the setup position is not good prep for real world situations. Practice your braces to avoid having to roll.
You don’t have to clear the surface with your hands, etc. to roll (see the Jackson videos). My opinion is that the boat is moving along with the current so its speed isn’t that critical. However, many paddlers will tense up in those situations and unconsciously alter their technique (more of a head thing than anything else). A pause to collect yourself before the setup could do the trick.
what works for me
On a day when the rolling gods look kindly on my efforts…
First get solid on a roll on both sides.
Second, feel which way the water is running around your upside down torso.
(For those like me who can’t convince eyes to open under water.)
Third, decide whether your best course is moving to the side where the water isn’t fighting you, or waiting for your speed to equalize with the current. In lesser levels of ww, you usually are safe waiting. If in a really gnarly spot, maybe not.
Roll without a setup
Rolling on the downstream side is good advice. Another posibility is rolling without a setup. For example, in surfing the easiest roll is to just stick your paddle into the front of the wave next to you and hip snap. Have a look at Eric Jackson’s rolling video and check out “advanced rolling”.
Equalizing speed myth
If you capsize in moving water, the time it takes for you (upside down) and your boat to reach the water flow speed is far beyond your breath hold ability. You want out right away! Your boat may twist and what you thought was the upstream side may not be that when you try to roll up.
Practice using your torso muscles under the water. In flat water lay upside-down under the boat and crunch and bring yourself up to a set up on your good side. Get a breath of air and now pull yourself under the boat and up on the other side. Get a breath of air. Practicing that is one of the best ways to bomb proof your roll. As you stated, the problem is not rolling up but getting yourself and paddle to a good position to roll up. You stated that you did roll up in a challenging current -congratulations. A sloppy roll that works is a good roll. I've done some of the sloppiest rolls you ever seen in surf but I got up.
Check out this article:
http://www.outer-island.com/bombproof.html
bookmarked. great article
I’ve done this to an informal degree. It really helps. Now I’m going to go do it more.
LOL
"You stated that you did roll up in a challenging current -congratulations. A sloppy roll that works is a good roll. I've done some of the sloppiest rolls you ever seen in surf but I got up."
What actually happened, I was under water for longer than I thought I could hold my breath. And I was still not able to get to a setup position I normally have. I thought I was in such a bad position the roll would surely fail but...
I was almost out of breath so I NEED to get some air. I know a the best way to replenish fresh air is to do a hip snap to get my head out of the water. (and might as well do a paddle sweep to help it a bit)
The next thing I know, my "air roll" got me UP! :o)
My experience
I’ve only practiced rolling in swift current on one occasion, so I’m by no means an expert. Honestly I found it no different than rolling in flat water. One thing I focussed on was setting up and rolling up as fast as I could. I used the momentum of capsizing to get me into the set-up position and without hesitation start the roll.
On flat water sometimes I hang out upside down for a bit to relax and get focussed for the roll.
what i’ve found
To be clear, my experience rolling in surf is more limited but operates by different rules than class 2-3 WW. In ww, I have found that some of my rolls have happened when I was at the same speed as the current just because of the (not huge) time it took to feel for my position. I haven’t ever felt that I was close on air in class 2. The water just isn’t pushy enough to cause a problem.
Surf is harderso far anyway. I have gotten up, but so far pick s less fortunate side and get knocked over while I am still getting eyes open and figuring out my exact position in the waves. That challenged my comfort under water for a longer time because the chaos of the washing water from the wave break has to settle out for me to be able to get a roll off.
In surf I agree - by the time the sinus flush is over and speed is equalized it has been a long wait.
In surf
I think in surf, rolling on the wave side is very important. Unless you can wait until the wave lets go of you and you come to rest (which can be a bumpy, even dangerous ride), you really need to roll on the side where the waves are coming from. Since you’ll nearly always capsize on the other side (away from the wave), it’s pretty easy with a little practice to just get used to rolling on the wave side. You do need to have equal comfort rolling on either side, but the good news is that rolling quick and on the correct side is almost effortless in surf because the wave does the work for you.
One more thing
Thanks for all the suggestions
I see this is mostly a sea kayakers forum. Majority of combat rolls are in surf. If I ever hit the ocean surf, I’ll remember all the advices. 
One tip I’m surprised NOT to see, is a standing suggestion from all WW paddlers. And it’s simple: roll on whichever side you’re closer, if you don’t get up, you’re already setup on the other side. Roll on that other side!
In rapids, the boat can spin and twist. So there’s not much point to “find the right side”. As one other poster pointed out, by the time you move your paddle to the “right side”, the boat might have been spun around and it’s now the “wrong” side! (also unlike in surf, the wave that capsize a paddler in WW are not the same wave you’re trying to roll in. So “right” and “wrong” side changes as you move through the rapid)
What I didn’t realize, was the difficulty didn’t come from not rolling up, but in not able to get to a setup position. Given my sloppy roll actually got me up, I’ll just roll in whichever side I’m ready. If I don’t come up, I’ll try the other side.
I have found - for me …
I surf down a wave then I might broach a bit. Now I’m running parallel to the oncoming wave. I lean towards the coming wave and brace over it and if it’s large enough, your face is in the foam while bracing and you can’t breathe. Then it whacks you over and you’re out of breath. I have resorted to sculling up just to get a breath of air then finish the job with a hip snap. It’s not an enjoyable experience. Usually after that I wonder " why am I doing this?"
I’m not a die hard surfer just playing in surf when it’s there on a paddle.
Not quite
If you capsize on a ferry your boat is almost always sideways to the current and stays that way for a while. Knowing the down river side is actually easy. If you capsize toward the side of the river it doesn’t matter which side you roll on. An example of that is Cucumber on the Lower Yough. Going through the hole at the end often capsizes people and typically they are still pointing downstream.
Still…
I haven’t capsized often enough to get the “feel” for the river upside down yet (OK, I haven’t paddled enough to capsize often). Still, I would think it’s easier to roll on whichever side that’s closest. The time it takes me to move the paddle to “the other side” seems to take longer than a roll attempt!
And if the first roll fails, the paddle is already on the other side. So is the body.
Interesting thread and good advice
I am interested in your thread because I am also at the stage of trying to bombproof my roll. For me too, a combat roll in real conditions is a different animal than a practice roll. So pardon the lengthy reply.
I find it helpful to take regular lessons from Dan Crandall, who is one of the instructors on "The Kayak Roll" DVD. http://www.amazon.com/dp/B0000AMKI5/?tag=googhydr-20&hvadid=13227164256&ref=pd_sl_kj1n93qnn_e That DVD has a number of good suggestions on bomb proofing your roll. If you can find a good local instructor, it is really worth it IMO.
Here are some of the things that Dan has done with me -
1. Have somebody strong toss and flip you to simulate turbulence. Here is a clip of Dan doing this to me in a pool. http://www.facebook.com/video/video.php?v=1123713269728 This is mild compared to what can be done. I remember the first time that I flipped in water big enough to scare me that I was thinking how similar it felt to some of the extreme shaking that can be done in this type of simulation.
2. Realize that if you can roll in flat water, you can roll in turbulent water - it will just feel different. One of Dan's main points is to focus on what you need to do rather than the different sensations or your fears or anxieties. In white water, your hands won't be feeling air maybe, and your paddle support on the sweep won't feel the same in the airy water. You may be getting tossed around quite a bit. But you will still roll up with the right motion. Be sure to use the feel of the wrists against your kayak for setup position rather than feeling for air up top. You may be tossed at such an angle that your hands won't feel air, but you can still roll up. It is easy to get distracted with unusual sensations and lose focus on what you need to do.
3. With an instructor or reliable friend, do drills on the river. Always warm up with some rolls. Roll in big wave trains and eddy lines just before a big pool. You can play a game where your friend or instructor can yell "Roll!" and you have to immediately roll. On my last lesson, you had to either catch the eddy higher than the instructor or else roll on the eddy line.
For me, these drill really worked. They gave me confidence to try some rapids that scared me, and when I did flip for real, the habits took over. Before this work, I usually bailed out in an actual capsize in scary water. Since this work, I haven't had to punch out yet. It made a huge difference in my confidence and approach.
Another drill we did - for knowing how much breath I had, was this. In calm water, flip over, but count for as long as you are comfortable before you roll up. Have a friend with a watch tell you how long you were under - you will probably be surprised how long you can hold your breath. And even a failed roll will give you a breath. I'm guessing that your problem was more unfamiliarity with what was happening than actual shortage of breath.
Here is another one - go under with your arms crossed and the paddle totally backwards/twisted/upside down - and fix it under water before rolling. Here is my son doing this drill with Phil DeRiemer (another of the excellent instructors on that DVD) http://www.facebook.com/video/video.php?v=1128263543482 This can train you to relax and focus in an unfamilar situation.
combat rolling as a regular exercise!
“On my last lesson, you had to either catch the eddy higher than the instructor or else roll on the eddy line.”
I like that drill! :o)
(although since I started learning playboating, capsize on the eddy line has become a rather “regular” event)