7.4.1 Shallow Water
Shallow water should generally be avoided where possible; however there are times when it is necessary. In shallow water there is increased bottom drag as well as a shock wave off the bottom of the boat reflected off the river bed which, when it rises underneath the boat will cause it to sit back in the water making it feel like you’re paddling uphill (in fact you are!). Attacking shallow water with extra speed can cause the shock wave to rise behind your seat and give the effect of surfing down it. If you maintain this speed, it may be possible to ‘surf’ across the whole shallow section.
Boily water is caused by flow hitting a very sharp object under water – such as a rock shelf or cliff face.
Boils are pretty tricky to negotiate, and are best avoided if possible. However there are occasions where the flow of a boil can help you keep the boat on line.
If you need to run boils, the “up and over” the middle of the boil route is typically the most straightforward, otherwise you will need to predict the push of the boils to help keep the line. Steer slightly into the flow and lean away to ‘carve’ the turn as well as to prepare your body weight to counteract the movement that will occur when your boat hits the boil. Remember, any movement that occurs to the bow of the boat will equally occur to the stern of the boat as you pass the boil, thereby straightening the boat for you, so be careful not to over-compensate your steering when you meet the boil. Stay loose in the boils and ‘go with the flow’ as much as possible, paddling powerfully with ordinary forward strokes.
7.4.3 Rock Pillows (cushions)
|In higher flow “pillows” or cushions appear on the front of larger
rocks. These pillows can exert a significant turning force. Try to run
parallel to the rock and allow it to push you sideways. If you steer
away from the rock, the turning effect will be exaggerated, and you
will move significantly off line. Beware running straight at the rock –
the pillow will not normally have enough force to direct one way or
Chop is small waves. Sometimes the waves are uniform and small, usually
with short wavelength, sometimes it is more confused water.
With modern large volume boats it is generally best to run chop
straight through the middle on the fastest water. It is important to
get good grip in the water with the paddle, by seating the blade in the
back of the wave, and using powerful strokes, drive through the chop.
The boat should stay flat and supported on the peaks of the waves.
If the waves are a little larger or the wavelength is a little longer,
you can still skip the boat from wave peak to wave peak, but it will
require a more determined effort. You will need to time and place your
strokes to lift the bow in the air slightly. Add to this strong use of
your feet and legs to lift and hold the bow in the air. The aim is to
fly the bow in the air to reach the top of the next wave, landing the
hull, roughly in the area of your feet, onto the next wave top. If
you’re successful the boat will run flat and dry. If the wavelength is
too long or the waves are too big, then it is no longer chop it is
waves (see 7.4.5 Waves)
Waves are bigger than chop. The waves indicate where the fastest water is, so ideally you will try and ride the waves. The aim is to avoid the boat pitching or the hull leaving the water or for waves to start landing in your lap. If the boat starts to pitch, the bow of the boat will start slapping onto the water and in large waves the bow will drive into the bottom of the following wave which is very energy sapping and loses boat speed. Waves coming over the deck into your lap are also energy sapping and lose boat speed.
To reduce pitching of the boat, time your strokes to the waves. Place your blade into the wave (usually the back of the wave) so that you get a proper grip of the water and apply power carefully to propel the boat forwards but not up or down.
If the wavelength is too short and pitching into the waves cannot be avoided or waves are landing in your lap, you will need to move to the shoulders of the waves where they are smaller and more rounded. This means moving closer to the eddy line beside the waves so you must be careful not to stray too far from the waves and out of the best flow.
Waves are rarely uniform and straight across a river. They are organic, rising and falling. They have rounded edges and are often offset to each other. Try to spot these and use the lower wave height to your advantage (see Figure 7‑2). The boat will often roll about as it passes through the offsets – but sit loose and allow the boat to run. Time your strokes so that ordinary forward strokes steer you through the offset waves. Your paddles should be deep inside the biggest part of the waves getting maximum grip, propelling your boat through the channel between the offset waves. Allow the hull of the boat to roll against the waves slightly so that more of the hull is in contact with the water. This will assist navigation through the offsets and reduce pitching. Make good strong use of the feet to steer the bow of the boat through the offsets.
If you need to steer in waves to change direction, time your steering stroke when the boat is most out of the water and in the air.
Because the boat may be pitching in waves and be in the air a little bit, ordinary forward strokes can have an unplanned steering effect. You will sometimes need to hold the boat straight by use of the feet to push the bow towards the pulling side and use of the hips to push the stern away from the pulling side. With a lot of boat out of the water it can be possible to steer the boat towards the pulling side by strong use of the feet and hips.
If waves are large enough to splash in your face, raise your chin up high so that water is dispersed away from your eyes and they don’t fill with water.
As mentioned earlier, be careful not to stray off waves into eddys. Beware of the boat bouncing off wave shoulders into the eddy. You will need to steer against the wave shoulder to prevent it. If you are very tired in the later stages of a race, it is sometimes better to sit in the waves and use less steering rather than risk an eddy out because you are too tired to steer against the wave.
7.4.6 Curling Waves
Offset waves diagonally across the river will normally cause the boat to mover along the length of the wave, and thus across the river.
This can be opposed by turning into the wave, or the effect can be used by turning inline with the wave.
When running corners and bends you are usually faced with a decision to either cut the bend or run with the flow around the outside. If you cut a bend it usually means you will be paddling through shallow dead water. You will need to carry extra boat speed into and through the slack. Accelerate as you approach the bend and maintain the higher speed to counteract the bottom drag of the shallow water. This obviously requires extra energy to do this. It is often better to simply follow the flow round the outside and save energy for later in the race. Test the two alternatives to determine the time advantage and decide.
When using the flow to travel round the bend, you need to ensure the boat does not start crabbing. The aim is to have the stern following the bow and the boat to be as parallel to the current line as possible. You should try and run the bend without steering strokes, only using ordinary forward strokes. You can do this by using the slower current, or the eddy, on the inside curve of the flow to draw your bow round the corner. If you find a bend causes your stern to slip and cause crabbing, you can counteract it by leaning back slightly as you approach the bend. This will cause the bow to rise slightly so that it doesn’t catch the corner so hard and, more importantly cause the stern to sink and resist the slippage more.
When running a drop you are trying to minimise deceleration by limiting how much water goes over the deck on landing and avoiding obstacles in the bottom of the drop (i.e. stopper, rocks, the ledge causing the drop). Ideally you will fly as far and as flat over the drop as possible. (see video clip - jumping stoppers)
Try to keep the boat flat fore and aft by raising your feet and legs to keep the bow up as you fly off the top. Time your strokes so that your last stroke pushes you off the top and in the direction you want to point when you land. The later the last stroke is taken the greater the push-off and the further you will fly beyond the bottom of the drop. Also, the later the last stroke is taken the greater the potential steering effect of the stroke as more of the boat is out of the water. The last push-off stroke will also give stability as the boat starts leaving the water. Try and keep a smooth paddling rhythm and technique continuing with your next stroke, as you land at the bottom, to maintain boat speed, and give stability. If you are landing close to an eddy or breakout it may be better to time your strokes so that the landing stroke is on the side of the eddy. This would mean your push-off stroke would need to be on the opposite side at the top of the drop.
If the bow is going to bury and water will cover the foredeck, sit the boat upright as you go over the drop. When a bow rises with water on its deck it will balloon up at the angle the deck is pointing, so if the boat is sat upright, it will rise up straight. If the boat is leaned at an angle it will pop out from under the water and exaggerate the angle and lean of the boat making it feel unstable as your body weight is thrown around due to the boat movement beneath you (see Figure 7‑3).
If you think the landing is shallow you may need to lean back to try and stop your bow hitting the bottom. If you think the landing is very shallow, you may need to reduce speed before the drop so as not to bury too deep.
If you think you will hit your stern, you may need to lean forward as you land at the bottom. This will reduce how fast the bow rises and therefore how fast the stern kicks down. If a stern hit is unavoidable, be prepared for the jolt. When the stern hits, it will briefly cause the boat to project in the direction it is already pointing, preventing steering, so ensure your boat is pointing in the direction you want to go at the top of the drop, before the stern hits (see Figure 7‑4).
A stern hit also exaggerates any lean on the boat with a jolting effect making it feel unstable as your body weight is thrown around due to the boat movement beneath you. It’s similar to the effect in Figure 7‑3.
A simple rule of drops is to sit up straight. This will give stability whether you expect water on the deck, a stern hit or both.
7.4.9 Holes (Stoppers)
Try and avoid running holes by sneaking down the side if you can. If that is not possible, running holes is similar to running drops except there is more water force, in the form of a stopper, to overcome. The objective is to minimise deceleration.
If the drop into the hole is not too steep you may be able to ‘fly’ your bow onto the top of the stopper wave and pass your boat over the hole supported by the peak of the stopper wave.
If the drop is steeper the boat is likely to drive into the hole. Remember the Rule of Drops and sit up straight. Choose the point in the hole where the most flow is exiting from the hole. This will minimise your deceleration. If the stopper has a sideways movement, generally you will try and shoot the hole at the side the stopper is moving towards. This is where the water is exiting and therefore fastest. Also, the boat will have the least sideways movement as it hits the stopper. Too much sideways motion will make it feel unstable as your body weight is thrown around due to the boat movement beneath you.
Generally you will try and shoot perpendicular to the hole so that the boat exits pointing in the same direction it entered. If you enter with an angle to the stopper it will increase the angle on exit due to the stopper dynamics and the ballooning of the boat. If the stopper is not too big this can be used as a deliberate method to turn the boat but obviously increases risk of instability.
If the stopper is large enough to splash in your face, raise your chin so that water is dispersed away from your eyes and they don’t fill with water.