I'm mostly worried about the kinds you'd run into in Cataract Canyon and Grand Canyon - large pourover types in the 20,000 - 40,000 cfs range.

What's the longest time a large hole can hold a swimmer? Is it usually just a few circulations until you get shoved out the side, or can it be long enough to actually drown you? Are there ever undercuts in the river bed that can snag you and hold you?

Is there anything you as a swimmer can do besides holding your breath and waiting it out?

Thanks!

Well, I haven't been in the huge ones like what you're talking about; I've been in plenty of sticky holes, though (mostly in my boat, but sometimes not).
As for what a swimmer can do: one piece of advice, which actually works often, is to dive down. I know you want to get to the surface and breathe and stuff, but diving down gives you a chance to catch the downstream flow and surface several feet downstream, beyond the backwash.
I'm sure others have mo betta info.

Such hydraulics are generally rare (fortunately), but could occur in even relatively lower flow situations. Even a few hundred cfs going over a low-head dam, or in a narrow slot-canyon pourover into a deep, steep-walled cauldron could create a nasty hydraulic.

The longest time it could hold a swimmer? Well beyond what you could hold your breath. I've seen logs, volleyballs, basketballs, and all manner of debris recirculated for days in the backwash of low-head dams.

Yes, there can be undercuts in the riverbed (or logs, large branches, or whole trees stuck underwater in the area below the drop) which could snag you and hold you under. These are certainly rare (especially at such locations as form keeper hydraulics) but nonetheless not impossible.

What you can do as a swimmer? Well, I think it is well covered in one of the old William Nealy books (and no doubt other places). I don't have any of those at hand, but my recollection is something as follows:

Your first choice is trying to stay in your boat, working to one edge of the hole or the other to try to work your way out. Failing that, sometimes you can find a spot where perhaps the backwash is weaker and you can paddle your way out. Or perhaps dig in an edge (of the boat) or get the flow to take the bow or stern under to 'ender out'. Or if you intentionally (or unintentionally) flip, the fact that your entire weight is no longer in the boat, but is now providing some additional buoyancy (you and your PFD), sometimes that is enough to cause the boat to flush out of the hole. If not, it may help if (instead of tucking as tightly to the boat as possible, as in setting up to roll) you 'hang out', extending your body, your arms, and your paddle as deeply as possible, to catch the downstream-flowing water deeper in the river. There may have been some additional options, but they don't come to me now. Other than a totally 'last chance' option. Before going for the full 'wet exit', I've heard some folks propose that you might intentionally pop your skirt off the rim of the boat and let the boat fill with water while you remain firmly in the saddle. Again, the lack of buoyancy can be enough to let you flush out of the hydraulic. The 'plus' side is that you are still in your boat, with your paddle (so no 'yard sale' -- yet!) and (by some theory) you can try to paddle toward shore and save yourself or someone else the problem of having to fetch your gear (or the possibility that you may lose it completely). The downside is that you are in a boat full of water . . . well, half-full, if you have equipped your boat with float bags . . . either way, it will paddle like a slug! If you can't get to shore immediately, you are trying to paddle a full boat through whatever is downstream. Your boat full of water is floating so much lower, and is so much heavier, the likelihood of it catching on a rock and pinning is waaayy increased. Your maneuverability will be almost nil, so you will mostly end up where the river wants to take you. (I have never really considered this whole option as being anything remotely 'viable'. I'm curious if anyone has ever used it successfully, and what the scenario was which made it feasible.)

Failing any of the above . . . once you are out of your boat . . . first, the river may flush you out as soon as you exit the boat (since you now lack it's bouyancy). If it doesn't, the first tendency and option may be to try to swim out (either downstream, or to one side or the other) if you can keep your head above water enough to do so. Depending upon the situation (the nature of the hole, the geology of the river, the flow, the size of the river, etc) an option which should not be ignored may be as simple as to try to find bottom. If the river is not too deep, it may be possible to just stand up and walk out! (YES, I've actually done that! More than once! On relatively low-flow rivers, at a bedrock ledge or boulder/pourover.) In larger rivers, or rivers with large rocks or with sieves and undercuts, this may not be a good strategy, as there may be significant risk of becoming entrapped, entangled, or pinned under or between rocks or other stuff in the drop or downstream. I've heard of (or seen) places where it may be possible (if there is a considerable 'hollow' behind the face of the falls) to get 'behind the curtain' and walk/crawl, swim/clamor your way to shore. Or to get to a spot where you could push off (as a swimmer in a swimming pool, pushing off the wall to accelerate away from it) or dive-through the falls. Failing any of those, caught in a hydraulic which keeps recirculating you, generally trying to 'go deep' is recommended, to try to catch the downstream flowing water. Another strategy is 'making shapes'. Try 'balling up'. Try extending your arms and legs (together) straight. Try extending them out to the sides. Arch your body into a "C". Stiffen up. Go limp. (Often holes flush the body after the victim has quit struggling.) Again, a last-ditch desperation measure I've heard proposed is taking off the PFD, hoping that the loss of that bouyancy may make the difference. I'm hard pressed to imagine that making enough of a difference, and having the presence of mind (and air supply remaining in my lungs) to try that (after trying everything else possible first!). And, the problem then is that (even if it does get you out of the hole) you are now completely exhausted and in the river without a PFD, and likely to drown anyway!

Well, again, these are RARE situations. If you boat high volume rivers, rivers in flood, class V-VI rivers, and so forth, maybe your odds of such a thing get a tad higher. But for most boaters, extremely few of these measures will ever have to be employed. There is never ONE RIGHT ANSWER. Rivers are almost infinitely different, as are water levels, rapids, falls, and hydraulics. What may be THE RIGHT thing to do one time and place may be completely WRONG another time (same place) or another place.

Good luck!

Rob Smage
AW member since 1992, volunteer since 2000, Midwest Regional StreamTeam Leader

It is educational to read the actual accident reports from both Grand Canyon and Cataract Canyon. Accidents are listed in a sidebar on the AW river pages.
[www.americanwhitewater.org]
[www.americanwhitewater.org]

Cataract has claimed quite a few more lives, but the typical scenario is the same. If the swim is long enough, people drown. There is no mention in any of these real accidents of victims caught in pour overs. Pour overs / holes initiate the problem by flipping rafts, then swimmers flush downstream. If not rescued fairly quickly swimmers can get too tired out and/or become hypothermic and drown. If you are in poor physical condition or are not wearing sufficient wetsuit or drysuit, you are in greater danger.

However, the number of fatalities is tiny considering the number of people who float through these canyons. It is likely that there are a few flips and swims in these canyons every single day, yet only a few people have died over many years.

If you swim in high water there is really nothing you can do other than to ball up, relax and try to conserve oxygen. You can flush a long ways before you pop to the surface again. When you do come up, it may be for only a fraction of a second, before you go back under. You have to get your breath in short unpredictable moments.

I swam out the bottom of Lava once at around 35,000 cfs and I was underwater for a long time. I am told, I reappeared about 200 yards below where I dissappeared. So it does not need to be a hole to hold you under for a long time in big water.

Typically most big water holes flush you deep and you pop up a long ways downstream. If that is the end of the rapid you are fine but if you flush into more serious rapids you can just get too tired and cold to get air when you need it.

Alright, thanks for the great advice! I swam the hole in House Rock in the Grand Canyon at about 20,000 cfs and know what you mean about the long swim. I don't think I was underwater for 200 yards though, probably only 50-60 but that was still the longest 20 seconds of my life. What really stuck with me though is how completely helpless I felt in the power of all that water. The cold didn't hit me until was out of the rapid but being in 48 degree water for 2 minutes really takes it out of you.

But that was with a commercial trip. The guides are professionals and deal with that stuff all the time, so I didn't worry about drowning very much. I've got 3 full canyon trips as a passenger in an oarboat and 1 Diamond-down trip as a rower, but that's about it as far as my experience goes. We don't have any professionals or guides on this trip so I'm just trying to play it as safe as possible and prepare for everything I can. It looks like Cataract will be down below 20,000 cfs by the time we hit the Big Drops next week so I'm not really that worried about it anymore.

My main worry was that hole on the right side at the bottom of Big Drop 2. From my research I figured the most likely way for somebody to drown on my trip would be if their boat was sucked into that thing sideways. From the videos on youtube, it looks like it gets bigger and meaner every spring than anything I've seen in the Grand Canyon. The accident database (awesome resource, by the way) listed a couple deaths from it. It looks like they were because of the cold, long swim and exhaustion, not from being held underwater by a hydraulic or obstruction though. I'm in good physical shape and won't wear myself out trying to fight the river so I'm not too worried about that part. Also according to NOAA the river should be down below 20,000 cfs by the time we hit it so I might actually get through right-side up.

Well, I've looked through about 100 accidents on the accident database and thought I'd share my findings for posterity.

It looks like the vast majority of the whitewater related fatalities I read about could have been avoided by observing one or all of the following guidelines:

1. Wear your lifejacket and make sure it fits properly.
2. Don't go alone.
3. Secure anything (ropes, gear, straps, clothing) that could
entangle you during or after a flip.
4. During life and death situations, being drunk is not a good idea.
5. Stay away from strainers and logjams at all costs.

Also, being old, very young, or out of shape makes you a lot more likely to drown. Of the people who were doing everything right but drowned anyway, most of them were under 15, over 55, or overweight. If you fall into any of those categories, make sure you have a Type V lifejacket to keep your face out of water if you're unconscious and a buddy that can fish you out and get you breathing again.

I just want to add a little to this thread. Even narrow creeks can cause features exhibited on big water if you catch them at flood. Be a defensive swimmer. By this I mean;
1) Have the right gear and know how to use it.
2) Have a plan. If your crew is scouting discuss a safety plan. If it’s a read and run situation know where you fit into the group. Read and run is a lot like a zone defense. The person who knows the river the best leads off followed by the person with the least experience. Next comes the boaters that may be ignorant of the river but still have solid skills and finally comes the one or two most skilled boaters. I like to call this mad bomber with country fill'in. Lead boater, Fill'in boaters, and Sweep boaters. There are endless combinations of this set up but remember if members of the group are running a different line there needs to be someone in there zone to give them a hand if the S$#@ hits the fan.
3) During every rapid have good river awareness i.e. where am i in the rapid and in relation to all of my paddling companions? Who is in my zone? In big water this is more difficult due to length of rapids and visual obstructions (Hugh waves and holes.). Good river awareness will enable you to predict, if lucky, where a swimmer will flush to or give the swimmer a good idea who the closest boat will be upon surfacing. Practice river awareness on smaller pool drop type rapids, run them mad bomber and see if you can register everyone at once.
3) Don’t panic. If you paddle long enough you will be a part of a rescue. If someone else is in trouble think first, is it safe for me to help them. Don’t make a situation worse by becoming a victim yourself. River hazards are not the only hazards in a rescue situation. A crazed swimmer can see your good gesture as an offer to use you and your boat as a piece of drift wood. This can easily flip you. If you think you can roll with someone clinging to the bottom of your boat try it in the pool, it's tough. If you’ve ever had any first aid training you know another hazard, body fluids. Bring a first aid kit that includes gloves and a CPR mask.
If you are the swimmer know what you are doing. Practice swimming. Balling up and staying relaxed is much easier if you have swam a lot of rapids intentionally. Despite what people say do not go completely limp. A limp person cannot stay in a tuck leaving there body open to leg and arm entrapments.
4) Know your abilities both as a paddler and as a swimmer. Think about all your options and don’t be ashamed to walk something, you can always set safety for others or take pictures.
5) Have fun. If you’re so scared that you’re not having fun what’s the point.
If you can be a defensive swimmer within your skill set and in a good group large features long swims and rough situations can be handled with intelligence. To quote a friend, “dude everybody swims, thank god y’all were there. Have you seen the beer?”

I had a fine swim in a hole down in Ecuador on the Jutunyacu, a big volume river, after a wet exit.

The main thing I remember is seeing the surface of the water a foot above me and expecting my pdf to bring me up quickly, the third time around I finally figured that this wasn't going to happen so I went deep and caught the current, I came up about 40 meters downriver, thus performing my first mystery move, sans boat.