teaching currents, w/o current!

Short version: I’m looking for suggestions on how to teach novice paddlers to maneuver in river currents, when the river has inconveniently decided to have no current.



Long version:



I am supposed to teach a class tomorrow on currents, to kayakers who can keep a boat directed where they want on flat water but who don’t have much background otherwise. My plan was to take them against the (tidal) current on the Hudson River for a while, having them practice in and near the eddy lines. But I scouted the route today at about the same tide that we will have tomorrow, and there was almost no current, not even at places where there is usually at least a little.



So I can think of two options, and I am open to others, or to specific techniques.



(1) Reconceive the course as a forward-stroke course and the on-water portion as a distance trip rather than a maneuvering trip.



(2) Stick with the currents course (which is what we advertised) and do exercises on techniques that would work in current, without being able to prove to the students that the techniques work, and without giving the students any practice at calibrating the technique to the current.



In the latter option, we have some pilings that students can practice maneuvering around. The only other exercise I can think of is to have student A provide resistance to student B’s turn: A would (gently!) bump their bow into B’s bow at a sharp angle, and B would have to calibrate a sweep to offset A’s turning force. The students are all adults, so I don’t think they would turn this into a jousting match, but I would be happy for other, better exercises.



Mark

Pray for a big barge to come by !
jack L

Sputen Duyvil
Can you get to Sputen Duyvil?



Seems like there is always something interesting happening around the bridge piers.

I like the bumping exercise
Have someone lay in wait behind a piling and bump someone’s bow as they come by, just a nudge the way a current would take it. Sing the “Jaws” theme while they are doing it.



Or, more seriously, could you set up something using a short tow line where they get pulled the way the current would? Just a thought - it may be a very silly idea.



Celia

I’d go with option 1
I have tried to teach students maneuvers that are dependent on current or current differentials such as forward ferries, back ferries and eddy turns and found it to be largely an exercise in futility. They really don’t seem to understand it until they can feel it, and that doesn’t happen in still water.



I would teach them what you can teach them well on flat water and wait for some current.

Drive 1 hr down US 1
To Yardley PA and throw your boats in the Delaware River.

Choose your currents here

– Last Updated: Aug-12-11 11:19 PM EST –

http://hudson.dl.stevens-tech.edu/maritimeforecast/

Pick a region and a time and you will see were the best currents are.

And also mention to your students that on tidal rivers (even without man made dam releases, rainfall, and 1.5 million gal a day sewage leaks), it is not wise to use the 1/12ths rule to predict current velocity versus water height.

For instance, East River current velocity reaches its fastest exactly at high tide.

worth a try
We are only a mile from Spuyten Duyvil. I will send someone up to check the currents there first thing, but I am not expecting much. The Harlem River should be near its slack current then.



A secondary issue: Technically, one isn’t supposed to play around bridge piers; one is supposed to transit and keep moving. I doubt the bridgekeeper would consider us dangerous, since he sees us go under all the time, but I have always avoided the temptation to take a group there and practice in the eddies. You are right that there are interesting currents there, and I often sneak in an eddy turn before I move on.



Thanks for the idea.



Mark

fascinating
Very interesting and complicated system at that web site. I will have to play with it more, but I discovered the relevant fact for tomorrow: usually the max flood at the George Washington Bridge takes three or four hours to decline to zero current, but tomorrow morning’s max flood is predicted to take less than two hours! Fabulous. I should have sent the river the email about the currents class.



Mark

that’s probably what i will end up doing
I think I will explain the problem, try some exercises, just in case they’re fun or effective, and then we’ll throw up our hands and go for a longer trip than we had planned. So it goes. Thanks for the advice from experience.



Mark

i’d love to, but…
…first we’d have to rent twenty cars and tie on twenty boats. Sounds expensive.



Mark

Rule of 1/12s

– Last Updated: Aug-13-11 12:17 PM EST –

Equating max flow of currents to high water/low water doesn't work. in fact, while they are dependent on one another, the times don't coincide.
Also, the rule of twelfths doesn't apply to currents, it applies to tide height. The rule used to approximate current speed is the 50/90 Rule. Tidally derived currents are listed in NOAA's data bases and there are multiple sites online that mine the data (NOAA's site can be a bit difficult to get around in if you're not familiar with it). Equating HW with max flood and LW with max ebb will always leave you disappointed.
While not quite related, I recommend your plan to change the subject matter of the course. Trying to teach how to handle currents in flat water just doesn't work.

I'm already editing this to include a link to NOAA's primary current stations for the Hudson River http://tidesandcurrents.noaa.gov/currents11/tab2ac4.html#33 . I also noted the difference between HW and max flood. At Spuyten Duyvil the difference is 22 minutes. In some places the difference can be a few hours.
Perhaps for your class, before moving onto forward stroke you could discuss the how and why for tides/currents and how to plan/calculate for them and how to calculate for strength/height at a given time during the tidal cycle. I know this gets more into the planning aspect, but part of coping with these conditions is knowing how to predict them and what affects them i.e. lunar cycle/apogee and perigee, how much precipitation there's been and how high river levels are etc.

When we teach river kayaking
we start in the pool. We set up an artificial eddy which is a float anchored in place with a weight (the “rock” and ropes going out from both sides (“eddy lines”). Students catch the eddy with a sweep stroke and proper lean. If they screw up one of us in in the eddy to bump their boat. Prior to that we paddle up and down the pool with the boat on edge with the goal of never letting the boat go flat. This doesn’t replace actual experience in current but does prepare them for actual current in a relevant way.

no current, no wind, no waves
Thank you all for your suggestions. In the event, we had a very calm day on the mile-wide Hudson, the world’s largest pond. The students took the lack of currents without complaint. We worked on sweeps and sideslips along the edge of the river for a while, and then we went on a nice scenic trip.



The main thing the weak current denied us was the chance to practice ferrying. I had assumed the idea of ferrying was too advanced for more than a mention, but some students seemed interested, so I presented the whole idea – on paper.



I will keep Dr_Disco’s simulated-eddy idea and Celia’s Jaws idea in reserve for another day. We are going to be doing more of these public-service classes. One lesson I learned from this: don’t commit early on to a curriculum; wait until the day’s conditions are known.



Mark

Removing some obfuscation
If you re-read NOAA’s web page, you will find that High Water and Max Velocity DO coincide for the East River; this is an unusual condition called a hydraulic current and has more to do with surface and underwater geography than lunar phases.



In fact the current can be Northbound on the Hudson and Southbound on East River at the same time.



The point is that the rule of 12ths should not be overapplied.

can’t resist…
Did you tell your student the booboo you made in understanding the different timing of current vs. tide height?



Personally (I have a strong math background), I found the “concept” of current and ferry angle not terribly useful as a “manuvering” issue but rather a NAVIGATION issue.



As far as manuvering, most people can easily figure out if they’re drifting down river, they simply need to paddle a bit MORE up river to end up where they want to. It’s mostly a practice thing. Without current, there’s no chance to practice how to make such corrections. The boring concept will simply be forgotten.



It’s only on long crossing with no landmark to do instantaneous corrections that mathematics comes into play. That’s more of a navigation issue how to CALCULATE ferry angle and follow a compass. But that doesn’t seem to be the goal of your class anyway.

you lost me
I don’t think I made a mistake about tidal current versus height. Do you mean the discussion about the rule of twelfths? That topic wasn’t part of my course; it was introduced by other posters on this thread.



I agree that, on a big, fairly slow river like the Hudson, ferrying is mainly a navigating skill. On a whitewater river, it can be very local and precise. Even on the Hudson, we have had people get pinned against pilings by the current, probably because the only way they knew to avoid an obstacle was to turn right and keep paddling forward. If they had known how to backferry, or even known the principle, that might have saved them some pain.



Mark

“Lost”
"…the only way they knew to avoid an obstacle was to turn right and keep paddling forward. "



Now, that LOST ME!



Why can’t they turn left? Or just cross down stream of the piling?



I once saw a fairly “experienced” paddler got pinned on pilings. Granted, it was a fairly strong current and the paddler simply under-estimated the current and used the wrong vector.



The Hudson is a good practice river because the current changes. That same feature makes it less ideal as a teaching environment, unless you’re very sure of your current prediction. Or, you end up in your predicament: no current. (or you could end up with so much current your “class” scatter all over the river from Albany all the way to the Verrazono Narrow)

Novice paddlers
We periodically encounter enough current around obstacles or out of small kills (streams) to confound novice paddlers even up around Albany. It is difficult to underestimate the ability of a new paddler to handle these situations. They often haven’t been in any current to that point, and truly do not understand that it can mess up their plans. So if they are drifting downstream they just doggedly paddle harder, straight, because they don’t understand that the water is having more effect than their paddling, or why paddling harder will have a useful effect, etc.



There are people who immediately show great instinctive responses and get it without much advice. But that’s not the majority of new paddlers I see up here. Most argue for having a few tow ropes in the group.

yes, very common

– Last Updated: Aug-16-11 4:23 PM EST –

Novice whitewater paddlers who notice an ominous obstacle coming up in their path often do one of several things.

Some act like a deer in the headlights, fix their vision on the obstacle, and basically freeze.

Some become anxious and paddle faster in an attempt to barrel a$$ around it. Often this just results in a more forceful impact.

Others point their boat in an appropriate direction and assume that the craft is going to go in the direction it is pointed. Unfortunately, because they are not paddling effectively the boat continues to go in the direction the current is taking it, right into the obstruction.

Back ferries are not intuitive for most paddlers new to paddling in current, nor is turning the boat upstream to execute a forward ferry.