Reading water: Lateral Waves, Using a Lateral.
Updated: Dec 22, 2022
We can use a lateral by controlling both the angle and momentum of our raft to quarter the wave.
Photo: A powerful lateral in The Narrows, Umpqua River, Oregon. Rower Sean Bowen.
We can read the force behind a lateral wave based on its angle to the main current, the volume of current / percentage of the river’s volume going into the wave, the backside of the wave, and the curl. Using the lateral wave will help you achieve your goal of moving your boat’s position laterally across the river or changing your angle as you crest the wave. Or both. Some of these moves might be called quartering, surfing, and typewritering.
Photo: This wave is backed up by a cliff wall and by a boil welling from underneath along the cliff. It would be impossible to break through and could flip a sideways raft. A mandatory quartering move.
Angle & Momentum: Hitting a lateral wave, we can control the way a raft moves laterally by controlling both the angle and momentum (speed times mass). The part of our momentum we are focusing on as we approach is our speed. You won’t have mid current control of your mass unless you dumptruck a passenger or two! Once we are surfing, moving people mass can control the surf and is an important tool. If things go sideways, don't forget to highside.
Photo: The right hand passenger high sides and the bow turns downstream, the rower ships his oar.
Quartering Angle: If we want to use a lateral wave to turn the bow, that is called quartering. Use a 45 degree angle to the force of the wave for quartering and hit it with one quarter of your bow. Conversely, in order to counter a lateral wave, we hit the wave with the entire bow at a 90 degree angle, which we call T up or square up. We learned about countering a wave in last weeks' write up. Again, to use a wave to turn, consider reducing that angle to 45 in order to hit it with the front quarter panel of your raft. For powerful waves, this partnered with push strokes, driving with downstream momentum, will allow the bow to turn with the direction of the lateral and straighten out to be in line with the main current as you finish out the downstream end of the wave. Quartering starts with your bow angled toward the wave, and ends with your bow facing downstream. Sometimes a single backstroke with the downstream oar can slow speed and turn angle as you ride up the face of the lateral and is all you will need to quarter a weak lateral. Whether or not your break through and over the wave depends on how much momentum you build into the wave as you approach and interact with it.
When do we want to use quartering? Quartering is useful when there are two laterals coming together in a downstream V and you want to hit one side first, turning into the second hit as your crest the V. Breaking down the V wave that is created by two laterals merging gives you more control over the feature by separating it into two features, which can be desirable when the power of each side is not equally matched. Quartering can also be useful when you need to turn the bow swiftly, but have limited space to do so with your oars or paddles, as in narrow creeks. Quartering off a lateral wave backed up by a canyon wall is common. Quartering can also be used to prevent breaking through to the backside of the lateral wave. For instance, when you would rather turn off the wave coming from the wall instead of hitting the wall! Use quartering or slowing your speed to prevent breaking through. Quartering is best used with the bottom end of laterals where the wave is not too retentive.
Photo: 45 degree angle to the wave, turning downstream as you hit the V.
Quartering Speed: build speed and momentum into the wave to quarter it.
Be cautious about setting yourself up to “get surfed.” You want to surf the wave, you don’t want to let the wave surf you. A quartering angle paired with slowing your speed too much by rowing/ paddling upstream might result in a surf paired with an angle change. This will be more out of control than a surf at a 90 degree angle squared up to the wave. Combining quartering with a surf can leave you accidentally sideways to the wave, so best to avoid that at first by only using quartering with building speed downstream while learning. You will hear boaters say “quarter the wave” to mean turning the bow into a downstream orientation off a lateral. The downstream V entrances to rapids of the Colorado River through the Grand Canyon are commonly approached using this technique or a downstream ferry.
Photo: Selway, ID. Would you quarter the downstream end of one of these laterals to turn into the crest of the V, or would you counter it by squaring up and breaking through on the upstream end of the wave?
Surfing Angle: Surfing is one way a boater can use lateral waves to move across the river. Use a 90 degree angle to the wave for surfing. Being perpendicular to the wave allows your boat to be more stable length-wise on the wave and gives you access to both of your oars (or paddles) for bracing and steering. Face upstream while intentionally surfing in a stationary location so that you can see the water you're interacting with. If you intend to surf laterally all the way across the river in a typewriter move, it's nice to face downstream so you can see where you are headed. Stay squared up to the wave regardless. Side surfing endangers the upstream oar, as it will effectively be run over by your raft/ sucked under the upstream side and pop out of the oarlock or even break. A paddler on the upstream side of a side surf will experience trouble getting in a stroke without the blade diving under the raft and the T grip end becoming a pole vault.
Photo: The author surfs a small wave on the Chetco River, Oregon, facing upstream.
Surfing Speed: Slow your speed by pulling, pushing, or paddling upstream in order to initiate a surf.
A surf on a lateral will take you from the top of the wave (upstream end) to the bottom of the wave (downstream end). The goal is to slow your downstream speed enough that when you reach the water falling down the face of the wave with gravity…you can fall down the wave as well. A proper surf on a river wide lateral wave can typewriter a boat all the way across in one swift motion! Focus on using your body mass and oar blade/ paddle to maintain a perpendicular orientation on the wave while surfing. Moving your mass will cause the raft to turn towards the heavier area. Surfing for play, paddlers will often jump into the bow of the boat. Surfing is great practice. Look for surf waves and lateral surf waves on rivers with ledge geology like Lake Creek, a tributary of the Siuslaw on the Oregon coast. Start out experimenting with small waves until you find that threshold between surfing and getting surfed.
Photo: an intentional side surf.