Pulling Canoe

[Guest]

For some reason this issue came into my head last night, and it has been bothering me a little bit. Maybe if I explain it well enough someone can ease my anxiety over it

This in a tandem, pulling to bow paddlers side. I can see my wife's stroke in the bow, it looks fine - vertical and no draw unless she wants. It happens more often to her left, that is her weaker side. I thought it was me getting lazy and sweeping but if I straighten the boat and stop paddling and let her go, it still veers off course, and to her side... Heavy J's every stroke and I can keep the boat going straight. I don't think I've ever noticed it so much to the right, but that could be coincidence.

Seen as how I stopped paddling and it still pulled to her side I figured it was some strange current or wind that was catching the boat. In the instances the where I have noticed it the water has looked calm, but maybe there is some slight current dragging us that way? And maybe I can feel it more than I can see it?

I also thought that maybe we shifted our weight around in the boat from sitting for a long time and we are heeling it slightly, but don't notice it... I'm not sure that would cause it to do that.

Any suggestions would be helpful, or at least things to look for... It might be technique, it might be the boat catching a tow, or maybe setup... but sometimes it is hard to tell and no one is there to point it out for us.

Many thanks!

 

[yellowcanoe]

Bow paddler has very little effect on turning on a forward stroke. That is due to the pivot point being closer to the bow than the stern. Its in the middle of the boat at a standstill but moves about a foot forward underway.

The mantra is that 99 percent of steering errors are caused by the stern person. Rather than list all the things to watch for I will just ask you one question. How far past your hip do you go with the power part of your paddle stroke? (not the J just the forward part)

 

[Guest]

I usually J or pull out when my lower hand reaches my hip. Sometimes I will J and pry right before my hip if I don't need as much forward motion as I do turning.

I should add this happens on occasion, not regularly.

Oh, I should add we've never had this issue in a pond - only in bigger water... hence I was suspecting some kind of current catching the boat.

Also if I stop paddling, it will persist. I thought it was me, but it doesn't seem to be.

 

[yellowcanoe]

OK..the most common thing that causes the veer is a stern sweep.. You don't seem to be doing that. Even if you just carry your bottom hand back past your hip but have been paralleling the keel line as soon as the hand gets past the hip, humans have a built in stern draw (same effect as a sweep).

Lately we have been teaching shorter forward strokes and the seated paddler ends their power stroke mid thigh. You can let the blade drift back for a J at the stern.

Windage can have a lot to do with how a boat handles. In heavy winds and big water we usually both paddle on the windward side, simply because its easier to keep the boat on track. (and you don't want to paddle on the downwind side..the boat will ride over the paddle and trip you up)

 

[Guest]

I know the boat pretty well now. It takes a pretty good sweep to get it off track. Also if I use a angle blade I use a shorter stroke - I'd like to switch as I found one I really like but my wife hasn't, and I don't want to switch until she does.

I guess maybe I wasn't reading the water right. Last time it happened was the 'calm' right before the storm. The water looked fairly smooth but I'm guessing we were just catching a small current broadside and it was pushing us off course. A thunderstorm was heading in fast so we were deadset on our course to shore.

 

[Glenn MacGrady]

I can think of six possibilities.

1. You are causing the yaw or veer with your stern paddling. You seem to have ruled this out.

2. The boat is heeled over and is hull-carving toward the bow paddler's on-side. You should be able to figure this out by heeling the hull to one side and the other to test out this theory.

3. Currents that are somehow differentially hitting the bow and stern. This raises the question, which you have not specified, as to whether this is happening in moving river water or in still lake water. Currents on rivers, even slow rivers, can swing and pivot boats in odd ways until you know how to read and adjust to moving water. However, if you are on a lake there should be no currents, so this theory should not apply there. Again, easy to test. Does the veering or yawing happen in flat, current-less lake water?

4. Wind-cocking or lee-cocking. If your gear load on the hull is imbalanced and the wind comes up, the lighter end of the canoe will try to swing downwind. That is, the heavier end will try to point into the wind. So if the stern is much heavier than the bow, and the wind is coming from the front or from the right or left quarters, the bow will tend to swing downwind. You can compensate for windage in a tandem canoe by having a sliding bow seat (and, better yet, a sliding stern seat too), or by having some heavy ballast -- like a pot of gold or a dead unicorn -- that you can shift fore and aft.

5. A twisted hull. This is rare, but some some hulls are defective with a twisted or bent shape. You can test this by looking down the lines of the hull, and by laying a straight edge or taut string along the hull.

6. Leprechauns.

 

[Guest]

I can think of six possibilities.

1. You are causing the yaw or veer with your stern paddling. You seem to have ruled this out.

Correct. I'd like to blame my wife, but I can't. And secondly I'd like to blame myself, but it doesn't seem to fit.

2. The boat is heeled over and is hull-carving toward the bow paddler's on-side. You should be able to figure this out by heeling the hull to one side and the other to test out this theory.

This is a big suspect. My boat seems to be very sensitive to bow position. I know I've had it do this before where my wife wasn't centered in the seat. I had her move and it fixed it. This last time I think I asked her to move, she did, and it didn't seem to affect it. I also shifted around and tried to make sure I wasn't heeling.

Next time I'll just try to heel it the opposite way. I don't know why I didn't try that.

3. Currents that are somehow differentially hitting the bow and stern. This raises the question, which you have not specified, as to whether this is happening in moving river water or in still lake water. Currents on rivers, even slow rivers, can swing and pivot boats in odd ways until you know how to read and adjust to moving water. However, if you are on a lake there should be no currents, so this theory should not apply there. Again, easy to test. Does the veering or yawing happen in flat, current-less lake water?

Most recent incident was on a lake. Seemed fairly smooth. I wouldn't call all lakes and ponds currentless though. A lot of time we get a wind current on the top and some of the ponds I've been on next to lake Ontario (which are actually connected) can have HUGE currents. These were very obvious and easy for me to see though. I mean this one pond I am thinking of after some good rain will push you from the inlet to the lake Ontario outlet with no paddling.

4. Wind-cocking or lee-cocking. If your gear load on the hull is imbalanced and the wind comes up, the lighter end of the canoe will try to swing downwind. That is, the heavier end will try to point into the wind. So if the stern is much heavier than the bow, and the wind is coming from the front or from the right or left quarters, the bow will tend to swing downwind. You can compensate for windage in a tandem canoe by having a sliding bow seat (and, better yet, a sliding stern seat too), or by having some heavy ballast -- like a pot of gold or a dead unicorn -- that you can shift fore and aft.

We have a bow slider in our Kevlar boat. I sometimes request ballast changes, but I rarely get it right.

Should the bow go forward (more weight ballast) in wind? At any rate it didn't seem windy...

5. A twisted hull. This is rare, but some some hulls are defective with a twisted or bent shape. You can test this by looking down the lines of the hull, and by laying a straight edge or taut string along the hull.

This I doubt because it doesn't happen very often. The boat tracks pretty well with minimal correction on glassy water.

6. Leprechauns.

I need 5 more drinks and I'll consider this one...

 

[yellowcanoe]

Trim.. If its off and stern light you steer like you have had five drinks. Unfortunate if you haven't; otherwise this might not bother you.. But the veering would probably not be consistent to one side. You can try marking dead level with tape.

Steering is easier bow heavy into the wind and bow light downwind. Yes your boat might be twisted. If you get to see Bill Mason's Prospector it was somewhat twisted..but I would not expect this in a composite boat.

Have another toast to leprechauns.

 

[Guest]

You guys are making me nervous. Time for that night cap.

I am going to pay close attention next time I'm out...

 

[Guest]

Learned a lot of about weight ballast today.

Crash course method: Put a 70lb mass in the boat which never stays in one place, in other words, my big dog!

5 minutes from shore the dog almost dumped us - the rail was at the water line, we were in motor boat hell with waves throwing us everywhere, and the dog was trying to get in the water. Somehow I managed to get us straight. My wife was a nervous wreck the whole time - everytime the dog got up she thought we were going over (and a few times she wasn't far off). It is much worse for her not being able to see...

The dog kept moving around, standing up, rolling over - it was the worst two hours I've spent in a boat. And yeah I can tell it was heel or wind-cocking that was the causing the pull, at some points we had both working pretty good... with the dog rolled on his back tucked into the bubble sides it looked as though we were Canadian style with two paddlers! This was in our other boat, so no twisted hulls. Unfortunately I could barely get the dog to stay low let alone get him in an ideal trim position.

I'm sticking with the 10lb Chihuahua for the water - she can run all over it doesn't upset the boat. Once our other dog is old and decrepit I will try again...

 

[Steve in Idaho]

Another thing that may be contributing to the confusion is that unless it's a hard-tracker, the canoe tends to continue on whatever course change that has been initiated. In other words - if a draw or a current sends the bow slightly off-track, it will tend to continue toward that direction unless acted upon by an opposing force (your j). So once the bow starts to drift, your bow mate's perfect paddle stroke will not stop it from veering in that direction without your help - or another lucky current.

 

[Guest]

Correct. I was teaching my wife how to paddle in the stern, and I had to explain to her that if I draw, she needs to counter J to stop the rotation of the boat.

I'm aware of those physical phenomena. And the fore/aft weight ballast makes sense to me, I'm not sure why I found it so elusive before. The dog helped. He was right behind the bow seat for most of the time and we were very bow heavy. Into a head/side wind I could literally feel the boat pivoting there and me swinging around following. If I stopped paddling, the boat would perfectly align with the wind, me being like the free end of a weather vane showing the direction it was blowing.

I guess the best way to really get a sense of this stuff is to have an extreme case. When things are subtle it tends to confuse me as to what the major contributor is.

 

[Guest]

I just had a major AHA moment earlier today!

It seems so simple now I can't believe I missed it earlier.

I KNOW (I think) why the Keewaydin pulls! It isn't consistent, but it should be consistent with the wind...

Bow height 20", stern height 17"! And looking at the profile it is pretty obvious...

Issue is the bow catches more crosswind than the stern.

 

[yellowcanoe]

The bow also has more rocker. The stern is relatively stuck. The bow can slide a little easier. She can compensate for the bow waggle when going across wind or up wind better than you can.

 

[Guest]

Any idea why they would design a tandem with asymmetrical sheer other than weight savings?

I brought this up to LDC and he had no ideas other than weight.

At first I thought the Eagle and the Keewaydin paddled very similar. The more I use both, the more I realize these little differences. The Eagle, being symmetric in sheer doesn't have this issue.

It is also faster than the Kee, despite being a symmetrical profile. Waterline lengths are the same. LDC insists it is the bottom profile, which is slightly modified on the Eagle. Keewaydin claims to be elliptical but it measures flat.

 

[yellowcanoe]

Differential sheer of course. Waveshedding ability is paramount in the bow. You need a little more height to get the required flare. Also secondary stability is paramount up there. Chief cause of capsize is bow paddler ejection.

In the stern broaching because the stern stem got caught in the wind going downwind is an issue. Breaking waves are less an issue..going forward into seas the bow paddler already took the brunt. Going downwind with seas you will be surfing and moving the same direction as the waves.

Having one tripping boat with symmetrical sheer, I won't buy that again.

I won't get into your measurement/ design issues. there is a long history of issues over whose design is what and how things are measured. When you say fast I trust you did this experiment scientifically..measure over a course with the same wind and same conditions?

Sheer has very little with speed. Deadwood does (under the waterline) You need to talk to more folks including canoe designers. Sometimes when we fall in love with a particular line of canoes we lose objectivity.

 

[Guest]

Oh I meant symmetrical sections, not sheer as far as hull speed. The asymmetric sheer I only brought up due to differential wind load...

Keewaydin is asymmetric in sheer and in cross section. Eagle symmetric in both.

Also I didn't measure the Kee, LDC did, and I'm only reiterating what he said. As far as speed we did a race on the same water and then switched boats. The Eagle was both times the winner.

Also I realize camber/rocker is a somewhat non-standardized measurement but the Kee is flat on the bottom from the side with only the very ends of the keel line turned up. IMO the bow does slip easier than the stern though. That boat responds very well to draw strokes and bow sweeps.

 

[yellowcanoe]

Not a scientific measure.

There is a long history here and I won't put it in print. I won't put it in a PM either. I do have a Hemlock boat and it does not measure out to specs. That is all I will say. I trust the measurements were done with a chalk line or laser level.

You are clearly in love and that is fine.

 

[Guest]

I agree it is not scientific. I make those kind of measurements all the time. I also am no stranger to racing, and no one disputes the person who crosses the line first even if the transponder stops working.

The Kee may be the better boat in certain situations. I only know which I prefer better.

As far as attachment I would get rid of either at any time if something that better suited my needs came along. And FWIW I am more invested in the Kee because it is more fragile and more expensive.

Measurements: I have no idea how these guys measure anything. I know how they are done in what I do. And I know there are many ways to do it incorrectly or to get non-repeatable measurements.

I can't imagine anyone in the industry is measuring boats on a CMM or actually doing scientific stiffness/strength testing on hulls. A lot of it seems to be based on subjective, qualitative opinions... but I don't really know for sure.

 

[red langford]

Did you try getting her to stop paddling and just you paddle, see if it still happens?

I can't see a slight breeze affecting the performance as much as you are describing. The reason I believe this is I have the same problem with my wife in the bow. I "fight" her stroke every step of the way and usually just end up asking her to stop paddling altogether and then the problem disappears. Never have the problem with anybody else in the bow, just her. I can't say for sure but suspect there is a "yaw" in the paddle angle that causes it. Looks normal from the back, but when she was paddling in the bow of a different canoe with my son at the stern I noticed it.

Maybe she is not realizing that she is putting a yaw on the blade angle and thus causing the "backseat battle" as I call it. After our last trip with the family my son was the sterns man for the second canoe and he said the same thing. If the entry angle is off 12-20 degrees this can cause the problem you are talking about more so than a few inches of higher profile on the canoe.

Another thought is I paddle a Prospector and it paddles the same, that is does not create any pulling effect, whether sitting level or heeled over and any number of angles. I actually prefer it heeled over. Empty in a moderate wind it likes to follow the breeze but not to the effect you described in your first post.