Canadian Canoe Routes

Boils and Whirlpools
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Author:  Alan Greve [ February 14th, 2004, 11:24 am ]
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Boils can be very unperdictable and very unstabling, coming up at any time. Although your first reaction will be to brace as one comes up at you. Your best and only real defence will be speed to get through the area of boilie water. I paddle the Ottawa (main) channel quite often and some of these boils can become quite large raising up to a foot in some spots. :o Whirlpools on the other hand cane be predictable and are found along strong eddy lines. On some eddy lines you could have two happening at once. Although unstabling as well can be quite a fun ride, more so in a solo boat. We often look for these whirlpools, we`ll paddle out from the eddy and wait for one to form underneath us. Hold on because some of the bigger ones will out do any Fair ride !!!!! :D If you should go over, hold on to the boat (if it has air bags ). Other wise you be doing a mystery move , poping up who knows where !! :o

Author:  Steve Galehouse [ February 14th, 2004, 7:45 pm ]
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Alan Greve wrote:
Boils can be very unperdictable and very unstabling, coming up at any time.

Sitting in a whirlpool always provides relief from my boils :wink:

Author:  HOOP_ [ February 15th, 2004, 10:56 am ]
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BOILS: When on a trip, fully loaded, and not looking for swim, these are really scary and something to avoid, although sometimes it is impossible to avoid them. On big water, there are almost always boils of some sort along the drop and especially at the bottom of the drop.

Sometimes it is brace and lean for all you are worth. The scary thing is that braces sometimes don't seem to work. The paddle sinks in the boils. The paddle should be in the water, prepared to pull water fore or aft, in order to brace the canoe. There are very strong within-boil currents can rush up and laterally, slamming into the side of your boat. You are essentially broadside to a wicked current that comes out of nowhere, grabbing the chine. And I mean out of nowhere. You can be pushed in any direction instantaneously in a boil, and when it is broadside, be ready with the mother of all braces which you will likely have to feather because the paddle may want to sink. Lean too far and you may also go for a swim, because unlike standard moving water, the boil current is irregular and unpredictable - as close to chaos as you are likely to get. So the powerful lean might fail as the broadside boil current suddenly decides to shut-off.

In fact it is difficult to know which direction to lean, because the out-of-no-where side current will take your boat suddenly sideways as well. The current is slamming into one side, but it will also slam into the other side as the water piles up on the opposite side to the current. You are the meat in the sandwich when this happens.

Forward power stokes are also stabilizing, so instead of bracing you may just want to pull forward and keep the boat under power. In fact the more I think about it, I think having the boat under some power in a boil is best. But not necessarily fast, because of those wicked side swiping currents.

Whirlpools. Again when tripping, fully loaded, they are not fun. Usually the big ones that are sucking down the river more than a foot are likely in section of the run where you don't want to be in an open boat anyway.

A variation on the whirlpool is the re-circulating giant flat "hole" along huge water rapids. These can hold a swimmer and boat indefinitely. They can also sweep a boat or swimmer back into the main current that might be too big for an open boat. Last summer on a solo trip on the Talston, I had to put in at the base of a falls at the end of a portage. The re-circulator was huge, and towards the direction of the waterfall base, where I definitely did not want to go (ugly). I had to seal launch from a log that I rigged, and paddle hard, counter-current to the re-circulator, and get beyond its grasp. Somewhat scary, and a must-make move. I judged it quite do-able and within my ability. But to have a screw-up on the move would have been bad. I was solo and so no throw rope would be available.

I would say leave these hydraulics for playboating, and avoid them when tripping when at all possible. But you will inevitably have to deal with them, and that is where the many hours you spend open boat playboating really pay off.

Author:  Chris K [ February 15th, 2004, 3:13 pm ]
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I'd be interested to know what would happen to you if you were 'sucked' into a large whirlpool.

Has this ever happened to anyone? Is so, how did you get out? Is it possible to ferry out once you are in? How big of an effect, if any, would gravity have in pulling you to the center of the hole?

I understand what causes boils, but I'm a little unclear on the phsyics involved in whirlpools, and so I've always avoided any large one like the plague, even when I'm playing.

What would happen if I aimed right for the middle of one? :o



Author:  Alan Greve [ February 15th, 2004, 6:47 pm ]
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As with many river features boils and whirlpools are no different. Learning to read water will be your best skill. As we`ve said these features are for the most part unperdictable, knowing where they may form is important. Which may suggest that the portage should be alittle longer. Like I said I`ve gone into some of these whirlpools on purpose ( never in a tripping situation ) and have went over, because the water sucking down, its very hard to roll. So needless to say I`ve went for a swim !!!! All`s I can say is the force of the draw is very strong, so holding on to the canoe ( with air bags ) is very important !!! The whirlpool should move it`s self down river and die-out. For those stationary whirlpools, STAY THE HELL OUT !!!! I can`t tell you much about the physics maybe someone else can.

Author:  paddlenorth [ February 16th, 2004, 12:11 pm ]
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On some big rivers (esp. in flood), boils can be the norm rather than the exception. Stay calm, keep the paddle in the water, and power forward. Like HOOP wrote, stay under power.

Staying calm and balanced is key.


There's a whirlpool on the Churchill River right before Black Bear Island Lake that A. Mackenzie wrote about. I don't remember his exact words, but he made it sound fairly scary.

The whirlpool we encountered was rather tame, similar to all the other modern accounts I've read, but there is a constriction there and I wonder if water levels were much higher when Mackenzie passed that way?


We paddled the Bloodvein in 2000, with really high water levels. I'd rate it a beginner's river, just b/c there are nice portages for every rapid, but in high water getting back in the river was a little sketchy in some places because of the boils.

If we were novice paddlers, this could have been a dangerous situation.

Author:  ogilvyspecial [ February 23rd, 2004, 6:18 pm ]
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Some years ago, my son, who was around 11 at the time and myself were paddling the lower Big Manistee River here in Michigan at very high spring water. The Manistee, where we were paddling always has a strong current but that day it was especially "pushy."

Along our route that day there were some underwater ledges that don't run all the way across the channel or even straight out from shore but run at odd angles pointing downstream. As we neared one of these ledges, out near the end, a giant whirpool opened up right in front of us and there was no choice but to go into it, down into it would be a better term.

The Dagger Venture17 that we were in tilted down as if it were heading for the bottom and I was thinking OH SH!T as all I could see was swirling water around my son in the bow. The Venture hit the other side and came to a dead stop then "wallowed" back & forth for a few seconds eventually breaking the vortex and we thankfully "popped up" to the surface taking on very little water in the process.

As soon as we did, my son turned to me and said, with a very stern look on his face I might add, "Dad, don't do that again" in a tone of voice that was utterly void of emotion but I could tell by that look that he meant every word of it.
I couldn't help but break out laughing it was so funny!

That's one day I'll never forgot, no matter how long I live.


Author:  Karen [ April 16th, 2004, 3:04 pm ]
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i think we paddled through a section of water on the thelon that had a lot of 'boils' (which were kind of goofy, but nothing of consequence), but i'm not sure i've ever seen a 'whirlpool' - is it just a big boil, or something else? when i read these stories, i think the whirpool is like something from a horror movie! can someone distinguish these 2 and explain what's causing them? (i.e. are the predictable?) thx - karen

Author:  Karen [ April 16th, 2004, 3:47 pm ]
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thanks for the info!

i'm still a bit confused about what's benath (or beside) the water to cause these funny patterns. any ideas?

Author:  jimdiane [ April 16th, 2004, 5:28 pm ]
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Last weekend we were on the Black and it was my second time out in my Atom C-1,very edgey!!! lots of boils, very scary!


Author:  bgervais [ April 18th, 2004, 2:08 am ]
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Karen, my understanding of boils is that (usually) they are the result of current being forced up from the riverbed. If you think of the river getting shallower as you paddle downstream, the deep water, especially if fast-moving, has to go somewhere, so it goes up, and disturbs the water above. It is unpredictable because once it hits the surface, it is already very turblulent because it is colliding with the surface water, and gravity is pulling it back down to the water surface.

This is why people have noted that sometimes paddle strokes can be 'swallowed' by a boil, because at the moment that you execute the stroke, the water happens to be going in the very direction you are directing the paddle, so the stroke has no effect on maneuvering your boat. It's an unsettling feeling, and I've never felt completely comfortable when on/in a boil.

A whirlpool frequently happens in a strong eddy or where two strong currents meet (esp if those currents are going in opposite directions) Just like the whirlpool in your sink when you pull the plug. What enhances a whirlpool is fast flowing surface water with slow moving deep water. If you think of an eddy at the side of the river, it is a re-circulating pool, basically cut-off from the normal flow of water - ie, you could put a stick into the eddy and it would happily go in a circle for a long time, never leaving. With a whirlpool, the main current is so powerful and dumping water into the eddy so much, that the water can't escape, and since gravity won't let it flow up, it goes down, under the strong surface water, and squirts out downstream somewhere. Many rivers have whirlpools that people can and do get sucked into, and they get pulled underwater, and pop up outside the eddy, somewhere downstream. I would recommend against trying one out though.

I have never heard of a whirlpool taking a whole canoe, but I wouldn't go so far as to say it's impossible.


Author:  wotrock [ April 18th, 2004, 6:44 am ]
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Karen wrote:
thanks for the info!

i'm still a bit confused about what's benath (or beside) the water to cause these funny patterns. any ideas?

this might shed a little bit of light on it. Other sites from a google search might help as well. Really hard to explain w/o diagrama & pix

Author:  Kim Gass [ April 19th, 2004, 5:36 pm ]
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Boils and whirlpools are common in tidal areas, and unfortunately they move around alot. Usually they are in areas where there are abrupt changes in channel depth and where there is alot of water moving. I think of them like horizontal holes and haystacks. Around here they are always moving as the tide depth is constantly changing. Boils unfortunately provide little bracing support and whirlpools often form on the edges of eddies (always changing shape too). The eddy line itself sans whirlpools can tip the unwary so think of them as little caution signs. Usually staying centered and balanced will get you through. I havent heard of any ship being sunk by one but in Passamaquoddy Bay there are some big ones that have turned tankers around.
They are kind of fun after you get used to it...maybe there should be Class 1 learning whirlpools, Class 2 and so on.

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