"My question now is from drifting down stream. I want to maximize the current during the race.
(1) What part of the river will push me faster. Center or the edge?
(2) And when should I try to go fast? After the corner when there is current . Or on the streight sections when the water is moving slow? I notice I had to really dig in after the inside of a curve to make forward progress. So I suspect that is the strongest point ."
You need to do a lot more of this to get a feel for what the water is doing, but here are some relevant comments.
(1) The part that will push you the fastest is wherever the main current is flowing. On curves, this will be along the outside bank, but you can often go faster “cutting the corner” a bit, simply because that’s a shorter route. You have to find a balance between the fastest current and the shortest route, all while keeping in mind the problem of getting tangled in the eddy, which is the water on the inside of the curve which is moving a lot slower, or is relatively stationary, or even moving in the opposite direction as the main flow. Also, the outside of the curve is where fallen trees are likely to be, and even if not, you will experience the effect of how the actual current is in three dimensions, going around the curve in a spiral, with the top of the spiral angling off toward the bank. That spiral current will pull you against the bank so you need to counteract that. You need to practice while observing these factors so you can figure out what to do for each individual curve. You may not make the best choice every time, but you’ll do better if you know how to interpret what you see.
On straight sections, the fastest current can be anywhere. The location of the fastest current will be affected by the direction and steepness of the previous curve, and the current’s natural tendency to meander. On long straight sections, the fastest current will likely wander around in its location between the banks, and very often it will split, with a shallower sandbar, gravel bar, or mud bar in the center of the river. Learn to read the water, rather than thinking some part of a straight channel will generally have the fastest current.
(2) I’m no racer, but it seems that the answer is to go as fast as you can or as fast as practical, when you can. Doing so will just be more complicated on the curves. At locations where you found the need to “dig in”, your boat was in the curve-induced eddy, and though you were working hard to go a straight line, your boat was actually going in a sharp curve through the water itself in order to go straight relative to the fixed landmarks that you using to mark your progress. That probably makes no sense to you right now, but a careful look behind you at the boat’s wake at such a moment will reveal the curved path that the boat is taking through the water itself, and it works out that way because that water at that particular location is moving in a direction you were not aware of while you were passing through such places. In in time you can learn to detect what is happening between boat and water just by feel, and you can learn to understand it better too. That in turn will help with the decision in #1 above, about choosing the best route when going around a curve.
Here’s a hint on negotiating sharp curves at maximum speed. The boat will steer toward the water that is moving past the hull at the faster speed. When going downstream, the current is slower toward the inside of the curve and faster toward the outside of the curve, and the water of that slower zone of current passes over the hull more rapidly, so the boat steers itself toward that side. This will be true at any location across the width of the channel, but is more pronounce adjacent to any obvious eddy line. Fighting that motion actually puts the boat on a curving path within the water that supports it, which is where the non-intuitive feel of the boat comes from at these moments (it will be intuitive if you understand it well). Often you can paddle strictly on the side of the boat that’s toward the inside of the curve and strike a balance between fighting the differential current speeds, and thus make the most use of power strokes and virtually zero use of correction or steering strokes. When going upstream, the zone of faster current nearer the outside bank passes over the hull with greater velocity than the slower current that’s nearer the inside bank (this is the opposite of when going downstream), so best use of power is on the side toward the outside of the curve. However, far better than to remember “rules of thumb” is to learn to be aware of the actual velocity (speed and direction) of the water relative to your boat as you negotiate the curve of the channel and simultaneously, the curve of your boat in the other direction through the water that supports it. You don’t actually need to understand this, and in fact, most paddlers don’t (not to this degree of detail at least), but I believe it helps a bunch if you do so I’m suggesting you focus on this aspect when negotiating the curves.
