What to Look For When Scouting a Rapid

I teach swift water rescue classes for Sierra Rescue, and we teach a huge variety of people. Anyone from military personnel, to firefighters, to raft guides, and scientists. Frequently people who don’t spend time on the river as raft guides or kayakers would tell us that they learned a bunch of awesome tools during the class, but didn’t have a great way to assess the risks of the rapids. So we decided to try and simplify everything and give people five things to look for in any rapid to answer two key questions: can I go?, and should I go?. These questions can apply to running rapids or performing rescues. The five things we settled on form the acronym S.H.A.P.E which I think works well so we can always be assessing the shape of the rapid.

Obviously strainers are a huge hazard in the river and need to be avoided at all costs. The number one cause of death in rivers changes between strainers and entrapments every year, typically depending on how big the winter was. Strainers also don’t just mean big trees, they could be fences, hoses, shopping carts, houses, sieves, or anything else where the water goes through, but we wouldn’t

Hydraulics (Holes)
Obviously as kayakers, we play in hydraulics so we don’t have to avoid all of them. But we should develop an understanding of what ones are ok to play in and what ones we should avoid.

We should always be assessing our own ability and the ability of our team. This doesn’t just mean our ability to run the rapid, but it also means our ability to set safety in the appropriate places. It’s also important to know that our ability can change throughout the day or even from rapid to rapid. By boating outside of our ability level we can put ourselves and our team at risk.

Pillows (or not)
If rocks are solid, meaning they aren’t undercut or sieved out, as water pushes into the front side, the first thing it tries to do is go over the rock. If the rock is too tall for the water to go over, it will fall back on itself on the upstream side, creating a pillow on the front of the rock, indicating the rock is solid and probably safer to operate around. If we don’t see a pillow, we can say that rock is potentially undercut or sieved out, and should be avoided.

Eddies (Exits, Egress)
Eddies are our friends. They provide us places to rest, scout, get out of the river, set safety, and regroup. If there aren’t enough eddies in the right places, it would probably be a good idea to portage or figure out a different way to run the rapid.

I honestly can’t really think of anything else I would be worried about when I’m running a rapid. To take some examples to the extreme, at flood stage a river could be full of strainers and running through trees on the bank, have huge hydraulics, I might have the ability to paddle the river, there are no pillows because the rocks are underwater, and there also aren’t many eddies. In a concrete flood canal, there are all kinds of strainers, there are low head dams, we might have the ability to run the canal, there are pillows on the fronts of bridge pylons, but there are no eddies for us to get out. Is there anything else you think we should look for before deciding to run a rapid?

– Carson Lindsay

Comments on “What to Look For When Scouting a Rapid”

No comments, be the first to comment!

    Leave a Reply

    Your email address will not be published.