OC1 boat pitch on turns

[Glenn MacGrady]

This is a question about both open boat design and open boat turning technique in whitewater.

The question is do you pitch the boat bow down, stern down, or keep the boat level on turns -- meaning eddy turns, peel outs, and any sort of pivots on current differentials?

As background to this question, there are two different pitch techniques used in advanced flatwater canoe turns and in decked C1 slalom turns.

Flatwater instruction emphasizes that turns are effectuated by sliding the stern. To increase the stern slide, the paddler is taught to pitch the bow down. This can be done via a sliding seat, by scooting your body foreword off the seat, or simply by lifting off the seat and onto your knees. All these techniques shift your body weight forward, pitch the bow down, and enhance the stern slide.

Regarding flatwater canoe design, the bow down pitch is made easier in a hull that has the longitudinal center of buoyancy (LCB) about at the center of the canoe. We can call this a symmetrical water line canoe, just for ease of terminology. In addition, the rocker line on the flatwater canoes preferred for turning is also usually symmetrical, meaning the same rocker in the bow and stern.

With decked C1 slalom boats, both the technique and boat designs seem to favor stern pitch turns. The boater effectuates the turn by almost burying the stern in a down pitch, by leaning backwards, and then pivoting with the bow lifted out of the water. These hulls appear to have asymmetrical water lines of the swede-form type, with the LCB aft of the geometrical center. I can't tell from videos whether they have symmetrical or asymmetrical rocker lines.

Now to my topic, which is about modern open whitewater canoes, slalom or recreational.

In my day, most popular whitewater canoes seemed to have generally symmetrical water lines and rocker lines. (The Dagger Prophet was a famous early departure.) I think most of us turned canoes by keeping the boat relatively level (longitudinally) -- that is, without any attempt at a pronounced bow or stern pitch. Of course, you can't really shift weight forward much in a whitewater boat when constrained by thigh straps or machines, anyway. Furthermore, older whitewater canoes were so long and voluminous that leaning foreward or back wouldn't alter the pitch very much if at all. In fact, I don't recall us even talking or knowing much about boat design or concepts such as swede-form asymmetry or the LCB.

Modern OC1's are so much shorter and less voluminous that forward and backward weight shifts can affect boat pitch.

So, do modern OC1 paddlers tend to enhance turns with backward stern pitching like the C1 slalom racers do? Are newer OC1's designed with asymmetrical water lines or asymmetrical rocker lines to enhance stern pitch pivot turns?

In this connection, Harold Deal has said his Shaman was designed with this in mind and he recommends using back shift stern pitch turns in that hull.

I'm genuinely curious, as my intimate familiarity with whitewater open canoes ended shortly after the time the Ocoee hull was introduced.

[TNbound]

I think what you will generally find is that most boaters are going to be leaning forward and tilting into the turn to help engage the chines in the bow of the boat. Most of the sharp turns I make use current to whip me around quicker. I've never been in a slalom C1, but it seems the benefit for them leaning back to pivot turn is that there is less resistance slicing the stern through the water than pushing around on the surface... Not a reality for an OC1.

As far as design, I believe my Blackfly Option is slightly asymmetrical. The L'edge I'm not so sure about. Looks a little more symmetrical. Depends on the boat I suppose.

[Glenn MacGrady]

Let me clarify that I am not asking about "heeling" the canoe laterally on turns, whether to the outside or inside of the turn. Of course, everyone is going to heel one way or the other to turn in all open boats, on both flat and white water.

I'm only asking about fore-aft longitudinal pitching.

Having said that, the Shaman evidently has sharper chines in the bow section, which can be engaged by leaning forward to pitch the bow down in heeled turns, preferably to the outside of the turn. Hence, according to Harold, the Shaman can be turned by pitching the bow down with an outside heel for a snappy turn in mild current differentials, or by pitching the stern down with an inside heel in heavier water.

I'm just using the Shaman as an example of more modern OC1 technique and design because it is one of the boats that sparked my curiosity on this subject.

[Shep]

This is a really fantastic question... When the Sweet Skills trailer got posted a few weeks ago, I think it raised questions very much related to this in my mind. I hope we here a response from Kelvin, who made those eddy turns and peelouts look effortless with a paddle position nearly at his hip (instead of towards the bow). I am also very interested to hear Kaz's input, since he seems to have revolutionized the design of open slalom boats with his designs.

My intuition tells me that, in an open boat, we cannot sink the stern but still reach forward with the paddle like a C-1 pivot turn. It will be interesting to play with once we've got enough water here to take the Option for a spin...

Shep

[Glenn MacGrady]

Perhaps I should let Harold Deal's published writing speak for itself regarding turning the Shaman. Perhaps I have misunderstood him. Here is how he describes turning technique in the Shaman hull design:

"Outstanding bow control can be achieved by combining knee pressure and appropriate stroke placement for the desired turning effect. Snappier eddy turns are possible when crossing mellow eddy lines by putting pressure on the outside knee and catching the bow chine. This may take some practice to get used to but can be done smoothly because of the soft chines and flared sides. The crisper the eddy line, the more dynamic the turn gets. Relative hull speed also affects the dynamics. Start mild and work up. It may soon become part of your paddling style. Classic inside leans remain the appropriate way to cross the more invigorating eddy lines. Outside leans can also initiate carved turns or spins. Edging is usually, but not always, complimented with a control stroke or turning stroke in the bow area. Hull speed must be sufficient with neutral resistance on both sides of the bow to be the most effective when initiating a directional change in this manner. This can be done with finesse and eliminate some turning strokes, but a stern correction stroke will likely be needed if too much pressure is allowed to build up on the opposing side. Using knee pressure can also help make minor adjustments in ferry angles by catching or releasing current flow on the bow."

"Develop the habit of leaning back to achieve the best turning characteristics. That is the biggest difference in paddling the SHAMAN. Major directional changes like spinning are executed with some stern lean to release the bow. The spin zone is actually behind the center of the boat so the paddler's torso becomes the pivot point. Turning strokes are often placed in the bow section and modified as needed, but it is important to shift upper body weight toward the stern for maximum maneuverability. The sensation is vaguely like a stern pivot with the bow being controlled in a sweeping motion. A paddler’s weight is naturally shifted behind center due to torso rotation during stern correction strokes or major turning strokes. More deliberate stern leans may be used for aggressive turns. Surfing steeper waves or lifting the bow over a wave crest or hydraulic are other examples. Tweaking the bow to the side of a wave crest or blocking waves are good tactics for keeping dry. It is usually counter-productive to lean forward to spin the boat in moving currents, except sometimes when utilizing current differentials. Dropping the bow or stern on the edge of an eddy, or into the corner of a hydraulic, or the face of a wave can also initiate a spin. Reverse strokes slow the boat in fast current so you can set up a spin or a back-ferry for sideslipping obstacles. Additional volume in the stern actually enhances overall stability in bigger water. Stern strokes are used more often in these conditions, too. Leans are adjusted as needed throughout playboating situations. Typically they are subtle or completely natural. Control strokes executed in the bow area make adjustments in the boat's direction while providing some forward momentum. Stern strokes are stronger and more effective when
maximum correction is needed."

[TNbound]

I'm only asking about fore-aft longitudinal pitching.

Yes, but I can't think of a time in my whitewater boats I've ever used a fore/aft lean without using the edges of the boat. Especially in eddy turns, the water and how the boat contacts it is what is causing the turn.

Leaning back to get the bow out of the water seems like something a little specific to which boat you are paddling. My Option or something like a l'edge or Spanish Fly has chines that run the length of the boat, so even if leaning back does get the bow up then you've just buried the stern.

Also may I add that leaning back leaves me feeling somewhat useless as far as paddling/bracing/generally driving the boat goes.

[Glenn MacGrady]

Here are two videos that illustrate the two different pitch turning techniques.

This is Karen Knight turning in flatwater freestyle technique with stern slides that are enhanced by subtle and aggressive down pitching of the bow. See especially her nose ender turn at 2:20. The canoe is a Bell Flashfire, which has a symmetrical water line and rocker line. (She starts her routine with the "Hiding Harold" move, named after it's inventor in the 80's.)

http://www.youtube.com/watch?v=fMyTTjKV-1U

These are elite C1 slalom racers turning through gates with aggressive lean-back stern pitches, in boats that look assymetrically swede-form.

http://www.youtube.com/watch?v=xliFn8pK ... re=related

[TheKrikkitWars]

You're making an apples to eggs comparison with the slalom boats...

The stern dip is using the power of the water to both turn quicker and preserve some forward momentum for when the turn finishes, it's totally unlike turning an open canoe in any way.

In my C1 Creeker and OC1 if I want to make a controled turn whilst moving I'll use my edges and keep neutral or forward trim to keep the edges/chines/rocker profile engaged, and the amount of edge/lean and forward lean to mediate how tight my charc is (more = tighter).

The only time I'd try to turn with the hull flat is if I have very little momentum and am floating in the flow (neutral trim) or if I'm trying to correct my line mid-rapid (in which case I'll lean back to reduce the amount of boat in the water, unless it's very pushy in which case I'll keep neutral for stability).

[Shep]

You're making an apples to eggs comparison with the slalom boats...

The stern dip is using the power of the water to both turn quicker and preserve some forward momentum for when the turn finishes, it's totally unlike turning an open canoe in any way.

I have very little experience in a slalom C1, so you could be right, but your explanation does not justify your conclusion. If you can get the stern of an OC more engaged in the water, and the bow less engaged, then you are approximating the effect of a pivot turn, by having the water push the stern around for you. If that's not the case, then we need a better explanation of what is happening.

The hypothesis that I think TNbound and I are both working under is that the rocker profile of the Option will allow you to shift your weight back, raising the bow out of the water, making it easier for current differential on the stern to spin the boat. From my reading on the Shaman, I think the goal is similar there. In either case, none of this assumes that the canoe has to stay flat from side to side. This fore-aft weight shift is in addition to edging the boat laterally.

Shep

[philcanoe]

This is a question about both open boat design and open boat turning technique in whitewater.

The question is do you pitch the boat bow down, stern down, or keep the boat level on turns -- meaning eddy turns, peel outs, and any sort of pivots on current differentials?

Yes

I tend to believe there is not one way to do anything in a canoe. There is quite likely as many ways to turn a canoe, as there are ways to turn one over (well maybe not, but certainly more than two).

One question ==> was your question limited to front and rear quadrants of the canoe, and not the (possibly) four, six, or seven that we routinely use in whitewater?

[ian123]

Seven quadrants? I must be doing something wrong.

[TNbound]

The hypothesis that I think TNbound and I are both working under is that the rocker profile of the Option will allow you to shift your weight back, raising the bow out of the water, making it easier for current differential on the stern to spin the boat. From my reading on the Shaman, I think the goal is similar there. In either case, none of this assumes that the canoe has to stay flat from side to side. This fore-aft weight shift is in addition to edging the boat laterally.

Shep

Sort of.

What I was trying to say is that on boats with a continuous chine (option, ledge, sfly, etc) even if you lean back to get the bow out of the water, you have just further engaged the chines on the back. Either way, you have chine to water contact of similar amounts. I doubt the different rocker profiles in the bow and stern will make a difference anywhere near what engaging the chines with a side to side tilt will.

And yes, moving all the way to the bow/stern of the boat worked for the chick in the canoe on glass-calm water, but that isn't where we paddle. The key to turning in whitewater (or paddling, for that matter) is using the water to your advantage.

[TheKrikkitWars]

I have one major problem with this leaning back idea...

It destabilises you, in a slalom boat that's not the case because sinking the stern gives you something to push/pull on, so you can bring your torso back neutral and stay stable, leaning back in a full-volume sterned boat you're just putting your body in a position where it's difficult to balance...

[John Coraor]

[The hypothesis that I think TNbound and I are both working under is that the rocker profile of the Option will allow you to shift your weight back, raising the bow out of the water, making it easier for current differential on the stern to spin the boat. From my reading on the Shaman, I think the goal is similar there. In either case, none of this assumes that the canoe has to stay flat from side to side. This fore-aft weight shift is in addition to edging the boat laterally.

Shep

I would agree with your general hypothesis, except for the reference to "current differential." If you return to Harold Deal's description of the Shaman, he notes that situations of differential current are the sole instance in which shifting weight to the bow is effective in accelerating turning: "It is usually counter-productive to lean forward to spin the boat in moving currents, except sometimes when utilizing current differentials. Dropping the bow or stern on the edge of an eddy, or into the corner of a hydraulic, or the face of a wave can also initiate a spin."

I believe that he is instead referring to a weight shift that substantially releases one end of the boat or the other, changing the location of the rotational axis of the turn by moving it either forward or back. In the case of Harold describing the Shaman, he's indicating that a sternward weight shift is most productive in creating this shift in rotational axis (obviously toward the stern) resulting in the bow being released to swing more readily.

However, in other OC-1 designs, you might find the opposite to be true. My experience in OC-1 designs is limited, but I can see this kind of difference evident in comparing Kaz's Hooter with his Ignitor. Both are 4-meter slalom OC-1s, but the Ignitor is a more recent "cab-forward" design with the paddler positioned closer to the bow and consequently it responds best when paddled aggressively from the bow. The stern is almost naturally released due to the cab-forward design, which results in the axis of rotation being shifted forward. However, I sometimes see Ignitor paddlers lean back toward the stern - not to accelerate a turn - to the contrary they seem to be using the weight shift to drop the stern down in fuller contact with the water to increase tracking while fully engaged in the middle of a gate (i.e. at a point when they don't want to turn any more because doing so would send the stern into the outside pole causing a penalty). Shifting the body to a neutral position or even more aggressively forward once the stern has cleared the gate returns the boat to it's normal cab-forward rotational axis, releasing the stern again and allowing it to swing more readily.

In contrast, the older Hooter has the paddler positioned more traditionally in the center of the canoe. A weight shift sternward in that boat readily releases the bow in the manner described by Harold Deal and allows the boat to be turned around a rotational axis that is definitely rear of center.

I suspect that, while limited to only two boats, this comparison is a good indication that whether or not a weight shift will help accelerate turning, and which direction shift (bow or stern) is most effective, is going to vary depending upon the boat design, the position or your seat in the boat (which can vary from paddler to paddler), as well as the particular paddling situation it is applied to.

John

[davebrads]

I will try to cast some light on slalom turning technique.

The primary advantage of sinking the stern on a slalom boat is that it shortens the waterline so that the boat turns faster. The downside to this is that it puts the brakes on. However, this is not necesarily a bad thing, after all you are turning in order to change direction so taking the pace off the boat could be a benefit. Also, a skilled slalomist will use the "pop" of the stern resurfacing to assist in accelerating the boat in its new direction, thereby regaining some of the energy lost in making the turn.

How does this relate to open boats? It doesn't really, you can only take advantage of this if you are in a slicy decked boat (and this is largely why I only paddle slicy decked boats).

What is happening in OC1s when you pitch forward or backward is that you are taking advantage of the rocker of the boat to shorten the waterline. This will result in a faster turn, but again at the cost of losing boat speed. The difference here is that there is no way of getting that energy back. So I would suggest ideally that turns should be carried out with a neutral pitch to maintain the speed on the boat, but if a sharper turn is required pitching forward is probably better simply in order to retain control of the boat.