What is… Flaring!

You will probably find that one person refers to the wide bottom of a trouser leg, the other will talk of shooting of firework signals and a filthier mind might perhaps think about the passing of wind… however, I’d like to talk about the edge change a kayaker can perform when he or she flies into an eddy.

 

Traditionally we are told to lean into the turn when padding into the eddy. We all know why this is necessary: if we don’t apply pressure on the thigh braces to lift the downstream edge, the motion of the boat sliding sideways over the relatively still eddy water will create friction and the boat will turn over.

 

 

So we always lift the side that the flow is pushing onto, to let the water pass easily under the boat.

 

 

Now if we have a look at what happens at some eddies. When the flow hits an obstacle, it gets compressed and starts to flow faster and sometimes even pushes up against the rock. This water will speed up and push back into the main flow as it passes the obstacle (see small arrows in the picture below).

If you’re looking from downstream, you can see a sort of a triangle where the water is extra thick.

So if we are paddling on the main flow, this re-entering water will actually push our nose back away from the eddy a bit, carrying us past the top of the eddy. The faster the flow, the more that happens. 

  

So what can you do to minimise the push from the side? The same as described in the first section of this article: lift the side that the flow is pushing onto. Does that mean that you are sort of leaning downstream before you enter the eddy: Yep!

But hang on: VERY IMPORTANT! To avoid hooking that edge into the eddy when you come in, you have to change edge really quickly as soon as you the nose of your boat comes across the eddy line. The more gradient between the flow above the eddy and the still water, the easier this is, because there will be a time of minimum water contact.

 

So what do you do?

• Approach the eddy like you normally do (lateral momentum, appropriate angle, blah, blah)
• Lift the upstream edge (think flow, not direction of the river) as you approach the water that pushes off the rock
• Make a last forward stroke on the side you’re leaning to
• Lift the opposite (downriver) edge as you cross the eddy line and…
• Put a stroke in on the inside of the turn (handy as you’re leaning to that side now anyway)

Clever people will have noticed that you’re taking your strokes on the side that you’re leaning to the whole time. That will give both support and control the turn.

 

On bigger drops this means that as well as opening up your edge to the oncoming water to let the flow pass easily under your boat, the bottom of the boat will also follows the shape of the water (more on that in the next article). The red line indicating the slope of the lateral flow coming off the drop is an ideal edge to have your boat on.

So that’s flaring: changing your edge when you cross an eddy line. If you get it right, it feels like flying!