A lot of river surfers are former ocean surfers who now find themselves landlocked for one reason or another. And rivers are safer in a lot of ways than oceans are. You may have to pay attention to flows, but tides aren’t an issue. No sharks whatsoever! Nor jellyfish, stingrays, or most other beasties that will give you a hard time in the ocean; crayfish are downright friendly by comparison. That’s not to say that rivers are safe though; river surfing dangers are different. Here are a few to consider.

Constant Force vs. Intermittent Force

Ocean waves tend to come in sets. You’ll have an intense period of energy flowing past a certain point, but then you get lulls in between the waves. Energy in a river doesn’t work like that. In areas where you’re in the current, the energy doesn’t go through significant lulls; while it may surge a little here and there, the energy flowing by a certain point is relatively constant.

Ankle Leash Entrapments

The distinction is important because of the impact energy moving through water has on your range of motion, and, for example, your ability to reach your leash. In the ocean, where the energy lulls, those lulls give you the opportunity to reach down to an ankle leash to release it if the leash happens to snag on something, trapping you underwater. In the river, you have no such luxury. If you’re wearing an ankle leash in a river and it gets snagged underwater in the current, the current is going to shove your body downstream, and you won’t be able to crunch up to get to your ankle and release the leash unless you’re in the gentlest of currents. Ankle leash snags/entrapments is one of the biggest dangers to river surfers.

So, if you’re going to use a leash, make sure it has a quick release near your waist that you can reach and release without looking at it. Even in strong current, you should be able to reach your waist to release your leash. And make sure you have a river knife easily accessible so you can cut through your leash, or someone else’s, if you need to.

Foot Entrapments

This constant vs. intermittent force problem also comes into play with foot entrapments. A foot entrapment occurs when a swimmer places their foot down in the current and their foot gets lodged under something, usually a rock. The current then forces their body downstream, preventing them from freeing the foot. Avoiding the problem is a matter of swimming, rather than walking, whenever you’re in water more than knee deep. If you can’t crawl on your hands and knees in the current, you shouldn’t be trying to walk.

Strainers

Another danger that stems from the constant energy flowing through rivers is the danger of “strainers.” Strainers include anything that has small enough openings in it that it’ll let water through, but not people, working like a colander or a strainer. Downed trees in rivers are a classic and common example. While they may look benign, if you are pushed under a downed tree in the current, the branches can snag you and hold you under, and the current can make it impossible to break free. Sometimes piles of rocks in the river can form strainers or siphons that will let water through but not people. Pay attention to situations where a lot of water seems to be flowing into a pile of rocks but only a little water seems to be flowing out – in those instances the excess water is probably flowing out under the rocks.

The best way to guard against these hazards are to keep an eye out for them, identify them, and avoid surfing features that have the potential to force you to swim into them if things don’t go as planned. If you do find yourself swimming towards a siphon or a strainer, do everything you can to get your head and body over the obstacle, rather than getting sucked under it. If you do get sucked under, try not to get snagged on any branches and swim towards any opening you can fit through.

Debris

The bigger the river and the higher the relative flows, the more you need to worry about debris coming downstream (looking at you, Glenwood over 15,000 cfs). Though a lot of debris will pass straight through a river wave, if the wave is breaking enough it can recirculate debris into surfers. Getting hit by a 40 lb log isn’t going to be much fun. Even more dangers are full-sized trees that still have limbs attached. The limbs are a significant entrapment hazard, and can  punch through wetsuits and entangle leashes. Avoid them, and if you see them heading downstream towards a surfer on the wave, let them know what’s coming. A loud whistle like a Fox 40 is a good idea; it’s hard to hear “log” over the sound of a wave.

“Keeper” Hydraulics

Whitewater rivers have the potential to form holes and hydraulics that recirculate a huge portion of the water flowing through them upstream. Pay attention to the size of this “backwash” heading upstream and consider whether it’s strong enough to recirculate you when you’re swimming. A low-head dam is a classic example of these hazards; there’s a reason they’re usually referred to as “drowning machines.”

Flush Drownings

This isn’t a danger unique to rivers, but it’s worth mentioning here because it tends to kill so many whitewater boaters. Flush drowning occurs when a swimmer isn’t held underwater, but the unpredictable nature of the swim, when the swimmer’s head pops out of the water, and exhaustion all lead to the swimmer aspirating water and drowning.

This is a pretty good example of how it can happen, even to an experienced kayaker wearing all the right gear and with safety help from another boater. Granted, the swim in the video occurred in a Class V rapid, but swims through any amount of whitewater can be punishing. Wear a PFD if there is any possibility you could be in for a long swim.

Accident Database

If you’re interested in more reading about how accidents tend to happen on whitewater rivers, American Whitewater has maintained an Accident Database for years, and it’s worth checking out. There is also a newer, less-formal accident database for river surfing that can be found here (and submit new reports here). Pay special attention to the accidents over the past five years or so in your state to see how things tend to go wrong, and stay safe out there.