Just out of curiosity, if you’re in a canoe (or kayak) in the main current and not in an eddy or on a slick spot is it possible to point your bow directly upstream and sit there without being swept backwards with the current?
I’m not sure what a “slick spot” is.
Isn’t this exactly what one is doing when they surf on a river or tidal race? (Staying in one place)
I’m honestly amazed at some of the ways people think they are defying the laws of physics on these boards. Understanding what goes on with ferrys and whether you can rudder-steer while drifting at the same speed as the current are two biggies also, as well as the idea that the boat’s hydrodynamics are different when going at different angles to a steady current (with the boat at equilibrium with current, not crossing eddylines), are things that really confuse some people.
Surfing is a different issue
With surfing, your boat is actually “coasting” downhill, so it’s being driven by gravity. The question was in response to what someone recently said here.
If you have a big magnet in the boat
And are floating over a huge iron deposit.
a slick spot is a glassy surface
in current you sometimes see glassy areas that are calm water. You can sit on one of these glassy spots and not be swept downstream, or you can use the glassy spots to work your way back upstream to get to a surfing wave or attain or whatever.
These glassy area “slick spots” are different from bubblestreets and dry highways (green tongues).
I have paddled only one kayak that could ferry without paddle input after the initial power stroke…a Prijon Combi 359 which is a 12’ combination touring/recreational kayak. http://www.wildnet.com/ww.asp?name=combi%20359%20-%20ww
If you use a power stroke upstream and set the bow just right the Combi will move exactly sideways without gaining or losing ground, but it will not just sit there and not be swept away.
Every other boat I’ve ever paddled required continual paddle input to stay in the same spot in moving water or to ferry straight sideways.
Sure just get in the hydraulic
every time we are in a WW river we do it.
If you get in a big time one and are not careful, just watch how it will suck you forward so the water coming over the little water fall will fill up your canoe as you sit there and say "holy crap I'm stuck "
We have a small WW river in the front yard, and it is always a contest to see who can sit facing up stream in one the longest.
Yes…Just drop the anchor
Warning “Do not let the anchor line become entangled in your PFD”
sitting there not moving
no eddy, hydraulic, or slick spot???
Sure, all the time, except during early spring…
Only we call it “stuck on a rock.”
Yesterdays whitewater run( and I use the term loosely), was like we were on thorazine. The 2 canoes and 2 yaks all experienced this numerous times. Good way to find new lines though.
Uh-Oh, Ferrys again
What you describe is a function of having lots of glide and directional stability. In such a ferry as all ferries, the boat is moving “straight ahead” as far as the water is concerned. The thing is, if you have a boat with lots of glide, you can slip from an eddy into the main flow and what you’ve done relative to water speed is exactly the same as if you give the boat a sudden forward shove on still water. In either case you will glide through the water for quite a ways, until the inertia is overcome by friction. In this case, the inertia that is being overcome is that of a stationary boat that will eventually be moved backward by the current. In the still water example, it’s the inertia of a moving boat, which will eventually slow down and stop. In both cases, that water movement past the boat, and the water’s force on the boat, is the same (as always, this doesn’t apply for short-term turbulent situations, and is best observed in broad, even currents).
very apt descripiton, thanks.
I’m honestly amazed …
“I’m honestly amazed at some of the ways people think they are defying the laws of physics on these boards.”
Don’t you think you could rephrase that so the recipient doesn’t feel as if he’s just been slapped in the face?
i love your words, “bubblehighways”,
very poetic. thanks
It is possible, but only if the hull angle is exactly right and the stroke cadence and power creates a hull speed which matches the current’s speed. One cannot sit there without paddling hard, as in an eddy or hydrolic.
I’m probably not understanding what you’re getting at here. In WW, surfing is possible when the hull is positioned in the sweet spot where upstream and downstream hydrolics are acting with equal force on the hull. Can you explain how gravity and going downhill come into the picture? Thanks.
The slick spots to which you refer are created by a drop in the river bed, the depth of which in combination with the right water depth can create a recirculating hydrolic which flows back upstream until equalized by the downstream flow. If paddled into from downstream they can actually pull the hull back upstream for a bit. It’s a lot like an eddy as far as effect on hull but just created differently.
The action of which you speak, are known as “power ferries” and can be done by many different hulls if executed correctly. The right execution varies with each hull and can require quite different technique with each.
In slow current there’s a way…
We call it skulling, working the paddle into a figure 8 It’s good for holding stationary against the wind as well.
Is it possible to sit still in current?
I've done it and enjoy doing it 'cuz its so crazy. Mainly in long boats with lots of glide. Possibly the very few paddle strokes used to correct position every once in a while might be just enough to give a forward push. Guideboatguy, I think you've given the most logical answer. Most of my correcting strokes are sweeps or just a strong forward stroke on the correct side. Still looks really weird. I'm not trying to counter the physics, I explained this to Patrick at ONNO and he said maybe something about the water passing the hull swirls and might produce just enough reverse push. The idea that it doesn't happen isn't true. It does, and I've done it often. Curious though about the why.
I'll do a GK here and invite anyone down here and I'll show it to you. Have to be soon though, the moving water's dryin' up.